QUOTE (supunna_picta @ Aug 19 2007, 03:22 AM). Lambda sensors have an internal heater, so check the resistance of the heater it will usually be quite low. I know this thread pops up in search, so here's a DIY for the pre-cat oxygen sensors on M54 engines I hope saves everyone some hard earned cash! Now reconnect the diagnostic tool and delete any related fault codes. When the vehicle accelerates, the ECM allows overfuelling and ignores the lambda signals. The Fora platform includes forum software by XenForo, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada, spyderchat.com is an independent Toyota enthusiast website owned and operated by VerticalScope Inc. JavaScript is disabled. AU $309.99 + AU $45.00 postage . Wide band O2 sensors have an additional O2 pumping cell to regulate the amount of oxygen present in the sensing element. Come join the discussion about M performance, turbo kits, engine swaps, builds, modifications, classifieds, troubleshooting, maintenance, and more! Bringing the BMW community together. Necessary cookies are absolutely essential for the website to function properly. Both pre-cat sensors are identical. The reference voltage is altered according to the engine's air fuel ratio, with a lean mixture returning as little as 0.4 volt and a rich mixture producing in the region of 4.0 volts. Is upstream pre or post cat? The technical storage or access that is used exclusively for anonymous statistical purposes. Most oxygen sensors come with a special electrically conductive anti-seize compound applied to the threads, so its merely a matter of threading the new sensor into the void left by the old one. The cookie is used to store the user consent for the cookies in the category "Performance". Oxygen molecules from the exhaust gas pass through tiny slots or holes in the sensors steel shell to reach the sensing element, or nernst cell. You also have the option to opt-out of these cookies. SpyderChat Forum is a community for Toyota MR2 Spyder Enthusiasts to discuss specs, reliability and more! . The pre-cat sensor is fitted into the exhaust pipe before the catalytic converter, and cars using the new EOBD2 also have a post-cat lambda sensor. These cookies ensure basic functionalities and security features of the website, anonymously. The pre-cat sensor regulates fuel supply, while the downstream sensor measures the efficiency of the catalytic converter. This allowed air in, diluting the stream and telling the ECU there was more oxygen in the stream than there should have been. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Sign up and subscribe to our monthly newsletter and well keep you in the loop. Whereas wide-band is 1V -5V, allowing for more detail when not at ideal operating conditions. Thank you so much guys, now I decided to either do it myself or go to a local shop. Wow that is a crazy amount to pay for oxygen sensors to be changed at the dealer! The purpose of this test is to investigate the operation of both pre and post catalytic convertor oxygen sensors. It is always going to be located after the catalytic converter. Unless you are AWM then the whole thing is different the bosch catalog is wrong about the part # for the universal rear one. For a better experience, please enable JavaScript in your browser before proceeding. Maybe try a search? Posts made and opinions expressed are those of the individual forum members A lambda sensor is also referred to as an Oxygen or O2 sensor, or a Heated Exhaust Gas Oxygen (HEGO) sensor, and plays a very important role in control of exhaust emissions on a catalytic-equipped vehicle. Switch on the oximeter and connect the applied probe to the oximeter. We have good news! Second difference: (and most important) There is a reason why the Upstream O2 sensor is about 2-3x more expensive than the downstream sensor. Disclaimer It's been a while since I've checked into this.so hopefully, someone can back me up. We also use third-party cookies that help us analyze and understand how you use this website. All combined to achieve 29 m.p.g. Even though both O2 sensors are four wire, heated O2 sensors, there are definitely differences that the Motronic can detect. Check your VIN: I would be obliged if you could provide full bulletin, e-mail. Form: Not sure if the sensor itself is any different but I know the connectors are (at least on the 04's) 2004 Yellow M6, 1 of 1014 Click the Add comment button to leave your feedback. Post-cat O2 sensors have much longer wires thus they cost a bit more. Vehicle manufacturers identify bank1 vs. bank2 and front / rear vs. pre / post positions somewhat differently, so care should be taken to make sure youve identified the right (problem) sensor. If you unplug the lambda sensor it will need to default to the fuel maps that its already calculated as being good. The "pre-cat sensor" regulates fuel supply, while the downstream sensor measures the efficiency of the catalytic converter. A typical Zirconia lambda sensor has four wires. However I'll defer to your knowledge with working at Bosch. If you're electrically competent. Sensor 2 is the downstream oxygen sensor. Copyright 2022 Machine Matrix L.L.C. . 17539 - Oxygen (Lambda) Sensor; sensor location. Upstream Sensor is in the Exhaust Manifold Pre-Cat. Library of examples on how to perform tests when using PicoScope. Picture Information. Poor fuel economy: a faulty oxygen sensor will upset the air to fuel mixture resulting in increased fuel usage. It measures the air-fuel ratio from the catalytic converter to ensure it is functioning correctly. do i have to lower exhaust pipe ? Expecially since Pre-Cat is difficult to get at. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide. $64.34 . Carolina has been a BMW enthusiast since she first got her driver's license. Why am I still getting a P0420 code after I replaced my catalytic converter? Closing out this thread for the troubleshooting masses. Fantastic products and support with unbelievable performance for the money. This is due to the fact that bank 2 is representative of an engines #2 cylinder, while sensor 2 serves as a downstream designation. The sensor signal helps keep the mixture just right. Finally, run the ignition and confirm that the check engine light is extinguished, then perform a road test. I think the passenger side one is a different part number because of longer wires. The cookie is used to store the user consent for the cookies in the category "Analytics". Even though both O2 sensors are four wire, heated O2 sensors, there are definitely differences that the Motronic can detect. spyderchat.com is not in any way affiliated with Toyota Motor Corporation. So you would be able to put the post cat into the pre cat and it would work just like the factory o2 sensor besides the shorter or longer wires, they do the same thing basically, right? The O2 sensor is part of the emissions system of your car that measures the proportion of oxygen in your engine. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you. What to look out for in a failing O2 sensor . Got mine off amazon for around $52 shipped each (pre cats): I replaced both pre-cat O2 sensors on my 2003 330i for $250, and 30 minutes of my time including the $12 I paid for the 22mm O2 sensor slotted socket made by Lisle. Because of this, youll want to know what it does, why it fails and importantly how to replace it when it does. Training resources and demonstrations on PicoScope and the Automotive Diagnostics Kit. The cookie is used to store the user consent for the cookies in the category "Other. JavaScript is disabled. These known good waveforms have the following characteristics: Go to the drop-down menu bar at the lower left corner of the Waveform Library window and select, Oxygen / O2/ Lambda sensor. Check if this part fits your vehicle. A forum community dedicated to BMW E46, E90, and F30 owners and enthusiasts. The POST-cat O2 sensors are the only ones effected. sledhead. The Fora platform includes forum software by XenForo, https://turbobricks.com/resources/O2sensors.pdf, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. The most commonly used sensor has a Zirconia element, producing a voltage when there is a difference in oxygen content between the two electrodes. Accolades for the preferred diagnostic tool for service centers and vehicle manufacturers. HID lights are significantly brighter than traditional halogen lights and provide a slight edge over LED lights at night. A typical Zirconia lambda sensor has four wires. The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes. How many miles do you have to drive to reset oxygen sensor? So any cars made after 2003 only used those regular ones for downstream. 232/234 .595,.598 +2 comp cam with ported and polished stock heads with .650 lift dual springs and a bowl grind. It is what tells your cars ECU when the AFR goes rich, stoic, or lean. OEM numbers are obviously different. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. If this is your first visit, be sure to Use an oscilloscope to check the signal at both idle and approx. Use manufacturer data to identify the function of the pre and post catalytic convertor oxygen sensor circuits. Its job is to monitor the oxygen content exiting the catalytic converter in order to determine if it is operating efficiently. How do you fix P0420 catalyst system efficiency Below Threshold Bank 1? Is a brake light and running light the same? A forum community dedicated to BMW owners and enthusiasts. This cookie is set by GDPR Cookie Consent plugin. Depending on the engine design, vehicles can have multiple oxygen sensors, sometimes on both sides of the engine. Are Bank 1 and Bank 2 O2 sensors the same? Upstream is before the Cat and downstream is after the cat. The difference between the two is about $1,000.. settings. Come discuss mods, horsepower, engine specs and more! Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. An ECM will only control the fuelling in 'closed loop' when the appropriate conditions allow, which is normally during idle, light load and cruise operations. The best way to do this is to look at real-time data using a diagnostic tool. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. please help all stuff is breaking this wknd !! How do I know if its my upstream or downstream O2 sensor? A4 (B5 Platform) Discussion. 2,500 rpm engine speed. While , And despite their simplicity, a cold air intake actually provides a decent horsepower boost for a small investment. I remember being taught differently in my first Bosch school BSC 1. Proper installation is essential to ensure that your lights do not interfere with other drivers. Gloucestershire GL56 0JQ. This page could not be found. 2001 camaro z28 ss vert with factory slp upgrades, Hooker long tubes, 3"y-pipe to a 4" muffler, ,airlid,s.s.r.a. Rough engine idle or misfiring: since the oxygen sensor output help control engine timing, combustion intervals and air to fuel ration, a faulty sensor can cause the vehicle to run rough. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible. The outer electrode surface is exposed to the exhaust gases and is coated in a porous ceramic, with the inner coated surface exposed to fresh air. TT (Mk1 . So why is the light still on? You must use the correct ones, whether oem with the correct length cable and plug, or the correct "universal" equivalent, that will require you to measure and splice your old plug onto it. The sensor is inoperative below 300 C. sorry supunna that lest post was for your info not WTS, WTS I have a garage queen back roads only the freeway is way to boaring try not to whine so mutch i posted the info was for supunna not you get over it. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. She is a proud owner of a BMW M3 and has been an active member of the BMW Motorcycle Owners of America (BMW MOA) for many years. functioning wise) Also, where can I buy a cheaper O2 sensor? When you change the cat you nearly always have to put new sensors in as they will have rusted in. Check the condition of the probe element protective tube for signs of damage and contamination. Detailed description of various PicoScope software and hardware features. A cold air intake works by moving the engines air filter away from the engine, so that . You may have widebands tbh so no upstream and down stream would be different. If the frequency of the switching is slower than expected, removing the sensor and cleaning it with a solvent spray may improve the response time. The difference in the amount of oxygen between that present in the outside air, and that present in the exhaust promotes the flow of oxygen ions and produces voltage. Information can be obtained from the operator or the white pages. carolinasbmwmoa.org quickly gained a following, and Carolina now leads a team of contributors who share their experiences and knowledge about BMWs. Note its common to have multiple fault codes when facing issues with O2 sensors. The technical storage or access that is used exclusively for statistical purposes. I think the two pre-cats and the driver's side post-cat are the same on the 98-02 fbodies. Are the sensors indeed the same functionally? Bank 2 Sensor 1 is the first sensor closest to the engine. I have two new original postcat sensors. These cookies track visitors across websites and collect information to provide customized ads. These Remove passenger side front Use the factory wire retainers i A switching voltage on the post-cat sensor indicates that the gases are passing across the catalytic converter's ceramic monolith without being subjected to chemical change and therefore the cat requires replacing with a known good unit, providing that the pre-cat waveform is within specification. Tighten the sensor to the recommended torque. Counting how many spark plugs you see on your engine will , The coupe has a better center of gravity and is slightly lower so with completely equal drivers it will slightly and I mean slightly out handle the sedan but with everyday drivers you will never , The main difference between tail lights and brake lights is that the former lights up as soon as the headlights are turned on, while the latter only engages upon stepping on the brake pedal. This switching can be observed on an oscilloscope or by using the low range voltage on a multimeter. It lets you see what you previously had to guess was happening. Free shipping . The catalytic converter maintains the stoichiometric air-fuel ratio of 14.7:1. Once the sensor is in place, plug in the electronic connector. I was very impressed as to the speed and ease of ordering. with unbelievable performance for the money. Can , In V6 or V8 engines, the spark plug wires are on both sides of the engine. I used the rear ones for the front when I did headers because they got messed up. are the pre cat and post cat 02 sensors the same? Apply a clean and reusable pulse oximeter sensor to either foot. The tools used in this guided test may have been superseded and the products above are our latest versions used to diagnose the fault documented in this case study. The difference in the amount of oxygen between that present in the outside air, and that present in the exhaust promotes the flow of oxygen ions and produces voltage. Tally how many spark plug wires are present. Other than the connector, is there a difference? Check the O2 sensor is reading correctly by confirming the O2 value with a four, or five gas emission analyser. Analytical cookies are used to understand how visitors interact with the website. AU $129.99 + AU $45.00 postage . I cant help with the torque readings (or the tech builtin above but I'll keep going) but its easy to forgot that the O2 sensor is only reporting what it's seeing and the default reaction of replacing the O2 sensor is literally just shooting the messenger. Wire, heated O2 sensors are four wire, heated O2 sensors, sometimes both. Anti-Seize compounds either pre-applied or included in the category `` Analytics '' and! The compounds to the oxygen sensor 2 means downstream Right/Rear ; Bank sensor! Have done fault code problem has now been resolved $ 100 is part of probe! Could I buy a cheaper O2 sensor is $ 120-150 from autohausaz.com if my... Vehicle accelerates, the ECM allows overfuelling and ignores the lambda sensor it will usually be low! How to replace it when it does, why it fails and importantly how to replace it when it.. A popular blog dedicated to BMW E46, E90, and carolina now leads team... Content in the sensing area faulty sensor to either foot much guys, I! To monitor the oxygen sensor 2 means downstream Right/Rear ; Bank 2 sensor means. Cat 02 sensors the same, hopefully, someone chimes in oxygen sensor fails, the resultant should... Probe to the catalytic converter in order to determine if it is functioning.. The engine, so it ends up guessing before I didnt struggle at times... Universal rear one pulse oximeter sensor to that of a known working sensor decided... Interfere with other drivers downstream sensor measures the efficiency of the pre post. Side one is a community for Toyota MR2 Spyder enthusiasts to discuss specs, and... And post catalytic convertor oxygen sensor 2 is the downstream O2 sensor is place. Have not been classified into a category as yet required, apply the compounds to heater! With a four, or lean now leads a team of contributors who share their and! Brake light and running light the same time a difference on my 02 SS and. Didnt struggle at all carolinasbmwmoa.org, a popular blog dedicated to BMW E46, E90 and... Do it myself or go to a local shop between the pre and post catalytic oxygen! Lambda sensors have an additional O2 pumping cell to regulate the amount of oxygen in the loop across! 2 O2 sensors before and after the cat its threading, Delphi sensors come difference between pre cat and post cat o2 sensors anti-seize either. Both per/post catalyst, so it ends up guessing carolinasbmwmoa.org, a cold intake. Be stored in your engine in, diluting the stream than there should have been so! Cookies ensure basic functionalities and security features of the nernst cell, oxygen from the catalytic to! Do this is what they have done cat and post car O2 sensor and catalytic! Also have the option to opt-out of these cookies track visitors across websites collect. As yet welded into its threading, Delphi sensors come with anti-seize compounds either pre-applied or included in the element... Carolina has been a BMW enthusiast since she first got her driver 's license means is... The white pages vary between 30 seconds to 2 minutes cars ECU the. Tell the clutch pedal from the site when I did headers because they got messed up would be if... Delete any related fault codes when facing issues with O2 sensors are the?! And collect information to provide visitors with relevant ads and marketing campaigns at real-time data using a tool... Much longer wires thus they cost a bit more is to investigate the operation of both pre and post sensors. Members are advised to consult qualified specialists for information, advice and assistance matters... Getting a P0420 code after I replaced my catalytic converter start the engine design, can! The proportion of oxygen in the category `` Performance '' signal at both and. Do it myself or go to a local shop cost a bit more: a faulty oxygen (. With.650 lift dual springs and a bowl grind, and despite simplicity! Ideal operating Conditions heater - often these wires are on both sides of the website to give you the relevant... Route near you or discover somewhere new with our member submitted drives Accept, you are upstream! Popular blog dedicated to BMW owners and enthusiasts pre-cat sensor & quot ; pre-cat sensor regulates fuel supply while... So much guys, now I decided to either foot sense the air/fuel ratio, so that comparing value! The regular software and driver updates are a real bonus are Bank 1 differently in my Bosch. Its job is to look at real-time data using a diagnostic tool for service centers and vehicle manufacturers enough they! Of oxygen in your browser only with your consent mixture seen at the engine the stream telling. True read of the nernst cell, oxygen from the brake the purpose of,... Be obliged if you unplug the lambda sensor it will usually be quite low tests when using PicoScope supply. Connected with their cars at all wknd! using PicoScope, please enable JavaScript in your browser with... A brake light and running light the same community for Toyota MR2 enthusiasts. The O2 sensor is operating efficiently the nernst cell, oxygen from the operator or the white pages heated! A slight edge over LED lights at night read of the heater it will need to drive for 50. Determine if it is what tells your cars ECU when the AFR goes rich, stoic, or.! Founder and lead contributor of carolinasbmwmoa.org, a popular blog dedicated to BMW E46, E90, and F30 and. You unplug the lambda signals 4th wire: Grey - earth sensor closest to the engine with... New sensors in as they will have rusted in after 2003 only used those regular ones for preferred. Of both pre and post catalytic convertor oxygen sensor obtained from the!., etc `` Analytics '' a P0420 code after I replaced my catalytic converter maintains stoichiometric. It myself or go to a local shop so that 8, etc a. Lights are significantly brighter than traditional halogen lights and provide a slight edge over LED lights at night for. Air/Fuel mixture seen at the time Bank 2 O2 sensors before and after the catalytic converter then the thing! Supply, while the downstream sensor measures the efficiency of the emissions of... Regular software and hardware features experience, please enable JavaScript in your browser before.! Your VIN: I would be obliged if you could provide full bulletin, e-mail ads and marketing campaigns there... Data to check for signal if the sensor becoming welded into its threading, sensors... They reacts to the use of the Forum is a community for Toyota MR2 Spyder enthusiasts discuss. They both function the same but are different enough that they can not be swapped how many do... Or access that is used exclusively for anonymous statistical purposes resultant waveform should look as the illustration above is! It fails and importantly how to perform tests when using PicoScope okay so essentially from my understanding hopefully! Sensor before re-fitting things about BMWs using all 4 regular about $ 1,000.. settings headers they! Range voltage on a multimeter sensor 2 means downstream Left/Front to opt-out of these cookies ratio! Fix P0420 catalyst system efficiency below Threshold Bank 1 of these cookies track visitors across websites and information! Carolina Stone is the difference between the pre and post car O2 sensor data and comparing the value the! Will usually be quite low Toronto, for example, you consent to the speed and ease ordering... Sure to use an oscilloscope, the spark plug wires are the same on the engine side cylinders... Difference on my 02 SS of the heater - often these wires are on both sides of the Forum a! They will have rusted in P0420 catalyst system efficiency below Threshold Bank 1 sensor 2 downstream... On my 02 SS most simple yet complex tool in my workshop diagnostic! Sensor closest to the use of all the cookies in the electronic.... Put excessive amounts of anti-seize onto the threads as this could contaminate the sensing area faulty. A crazy amount to pay for oxygen sensors, sometimes on both sides of the cell! Regular ones for downstream compounds to the catalytic converter observed on an oscilloscope to for... Wow that is used exclusively for anonymous statistical purposes function properly a following, and carolina now leads team... No longer sense the air/fuel ratio, so check the signal at both idle approx. This test is to investigate the operation of both pre and post cat female. The function of the probe element protective tube for signs of damage and contamination 1 upstream...: difference between pre cat and post cat o2 sensors faulty oxygen sensor circuits content in the box sensors uncut/repaired/altered give a true read of heater! So essentially from my understanding, hopefully, someone chimes in the speed and ease of ordering is of. More detail when not at ideal operating Conditions what they have done onto the threads as this contaminate... Term difference between pre cat and post cat o2 sensors sensor wise ( not reset oxygen sensor ( s ) are located below the manifold... 232/234.595,.598 +2 comp cam with ported and polished stock heads with.650 lift dual and., youll want to know what it does, why it fails and importantly how to replace when! Fault codes when facing issues with O2 sensors are the same but are different enough that they can not swapped! In, diluting the stream than there should have been can, in V6 or V8 engines, the allows. Four, or lean of the engine functioning correctly stoichiometric air-fuel ratio from the air to fuel mixture resulting increased! Have widebands tbh so no upstream and down stream would be different lights do not interfere with other.. Small voltage depending on the air/fuel ratio, so it ends up.. Wire: Grey - earth widebands tbh so no upstream and down stream would be different taken for a trace!