difference between pre cat and post cat o2 sensors

Bali Administrator 2013 X1 M-sport Joined Aug 18, 2012 22,344 Posts When you change the cat you nearly always have to put new sensors in as they will have rusted in. If you unplug the lambda sensor it will need to default to the fuel maps that its already calculated as being good. Even though both O2 sensors are four wire, heated O2 sensors, there are definitely differences that the Motronic can detect. The purpose of this test is to investigate the operation of both pre and post catalytic convertor oxygen sensors. Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. That's where my misconfusion came from. Come join the discussion about Bimmerfest events, production numbers, programming, performance, modifications, classifieds, troubleshooting, maintenance, and more! If the exhaust gas mixture is too rich and there is too little oxygen in the exhaust, a signal is sent to the engines Electronic Control Unit (ECU) to decrease the amount of fuel added into the cylinder. 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. Proper installation is essential to ensure that your lights do not interfere with other drivers. Free shipping . I know there wasnt a difference on my 02 SS. Read any fault codes using a diagnostic tool. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. A vehicles (bank 2, sensor 2) O2 sensor will be located behind or downstream of the catalytic converter on the bank which corresponds to the engines second cylinder. Can , In V6 or V8 engines, the spark plug wires are on both sides of the engine. carolinasbmwmoa.org quickly gained a following, and Carolina now leads a team of contributors who share their experiences and knowledge about BMWs. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. This cookie is set by GDPR Cookie Consent plugin. OEM numbers are obviously different. We also use third-party cookies that help us analyze and understand how you use this website. The pre-cat sensor regulates fuel supply, while the downstream sensor measures the efficiency of the catalytic converter. TT (Mk1 . Carolina Stone is the founder and lead contributor of carolinasbmwmoa.org, a popular blog dedicated to all things about BMWs. Lambda sensors can have a heater element which heats the sensor to its optimum operating temperature of 600 C. This allows measurement of a much wider air/fuel ratio. 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. These Remove passenger side front Use the factory wire retainers i How do I know if its my upstream or downstream O2 sensor? Is bank 2 O2 sensor upstream or downstream? How do you fix P0420 catalyst system efficiency Below Threshold Bank 1? 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 Sensor 2 is the downstream oxygen sensor. This is a TSB regarding the P2096 problem. The POST-cat O2 sensors are the only ones effected. Reading the trouble codes will tell you exactly which sensor is in need of replacing either the upstream (top) or downstream (bottom) sensor and on what bank (side) of the engine. with unbelievable performance for the money. Should I replace both oxygen sensors at the same time? Because many late model vehicles have multiple oxygen sensors, be sure you correctly identify the bad sensor so you do not mistakenly replace the wrong one. Downstream Rights means the rights that are acquired from the Downstream Operator by a User or the Downstream System counterparty user, in order to receive the Regasified LNG at a Regasified LNG Delivery Point. Real-life case studies show how the professionals use PicoScope to diagnose vehicle faults. I know that replacement sensors show the pre-cat part # is different than the post-cat part # - the visible difference is the wiring length but I would like to know if they are in fact different internal parts for the sensor itself (different voltage or heat range?). 2001 camaro z28 ss vert with factory slp upgrades, Hooker long tubes, 3"y-pipe to a 4" muffler, ,airlid,s.s.r.a. Library of examples on how to perform tests when using PicoScope. Most cars have at least two oxygen sensors located throughout the exhaust system; at least one in front of the catalytic converter and one or more downstream from the catalytic converter. There is no different part number for bank1 and bank2. Check the O2 sensor is reading correctly by confirming the O2 value with a four, or five gas emission analyser. i.e. If necessary, refer to the vehicle manufacturers data to find the correct value to compare against. While , And despite their simplicity, a cold air intake actually provides a decent horsepower boost for a small investment. Analytical cookies are used to understand how visitors interact with the website. The support I have received from Pico over the years has been superb. read the wiki, all common air leask are there, hi y have 2 codes po155 heated oxygen sensor bank2 sensor 1 (ho2s21) sensor heater circuit and po135 heated oxygen sensor bank 1 sensor 1 (ho2s11) sensor heater some vary can tell me the locations on this sensor and part #s or were i can buy it cheap thanks. The product is excellent. The downstream oxygen sensor(s) are located in the exhaust pipe, behind the catalytic converter. If this is your first visit, be sure to Closing out this thread for the troubleshooting masses. 325 e, i have 03 bmw 330xi and bank 2 oxigen sensor wire got burn out touching the four wire, i split it them but now get code p0031,p0600,p0051,p0037 and p0057 can anyone tell me how to check the voltage on those wire or the wiring schematic. If you are boating from Kingston to Toronto, for example, you are heading upstream. 3rd wire: Black - signal AU $309.99 + AU $45.00 postage . functioning wise) Also, where can I buy a cheaper O2 sensor? Pre Cat and Post Cat O2 Sensors For Suzuki Swift Sport RS416 1.6L M13A M16A . What to look out for in a failing O2 sensor . Use live data to check for signal if the sensor wiring is difficult to access. The technical storage or access that is used exclusively for statistical purposes. Machine Matrix strives to provide top-quality vending machine technology to clients, going above & beyond in all aspects of service to ensure ease of use and a hassle-free experience. The time taken for a good trace may vary between 30 seconds to 2 minutes. The pre catalytic converter signal transitions, from lean to rich or vice versa, take around 0.5 s. The post catalytic converter sensor signal. So any cars made after 2003 only used those regular ones for downstream. Download manuals, brochures, posters, and training materials. Contact information for direct sales and support queries, plus our network of global distributors. Hi my VIN is 98 Z4U 64 1458, so would this need the upgrade as I seem to be suffering from this issue? This help topic is subject to changes without notification. How do I know which oxygen sensor to replace? I'm no mechanic but if there is no difference at all, then why is the front O2 sensor $98 and the rear is $220?? Techincally all 4 O2 sensors are the same. A typical Zirconia lambda sensor has four wires. Could I buy universal one, if not why? settings. The Waveform Library is a global database of waveforms uploaded by PicoScope users. $89.05 . 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! The most commonly used sensor has a Zirconia element, producing a voltage when there is a difference in oxygen content between the two electrodes. Both Titania and Zirconia sensors, when working correctly, switch approximately once per second (1 Hz) and will both only start to switch once the normal operating temperature has been achieved. Oxygen sensor 2 is the downstream O2 sensor in relationship to the catalytic converter. I have two new original postcat sensors. Sign up and subscribe to our monthly newsletter and well keep you in the loop. You never never never get anything done at the dealer, NEVERRRRRR. Four-cylinder engines have two sensors, while V6 and V8 engines have four sensors. The upstream oxygen sensor(s) are located below the exhaust manifold flanges and above the catalytic converter. Last one . The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network. 17539 - Oxygen (Lambda) Sensor; sensor location. Carolina has been a BMW enthusiast since she first got her driver's license. Its job is to monitor the oxygen content exiting the catalytic converter in order to determine if it is operating efficiently. The cookie is used to store the user consent for the cookies in the category "Performance". Our garage has checked leaks and wiring and this is what they have done. The best way to do this is to look at real-time data using a diagnostic tool. Even though both O2 sensors are four wire, heated O2 sensors, there are definitely differences that the Motronic can detect. A constant high voltage output from the Zirconia shows that the engine is running constantly rich and is outside the ECM's adjusting range; whereas a low voltage indicates a lean or weak mixture. Are Bank 1 and Bank 2 O2 sensors the same? Too much fuel produces hydrocarbons and carbon monoxide. The regular software and driver updates are a real bonus. Once unscrewed, discard the old sensor and replace with the new unit. If you decide to do this long term, you will experience problems. We have good news! Are the sensors indeed the same functionally? 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. Connect a diagnostic tool, such as Delphis DS, select the correct vehicle and read the fault code(s). The technical storage or access that is used exclusively for anonymous statistical purposes. Where as before 2003, they were like yours using all 4 regular. LS1GTO.com is a forum community dedicated to the LS1 Pontiac GTO. As you drive your car the computer will monitor all the sensors and register the results. O2 Sensor Location. Find a route near you or discover somewhere new with our member submitted drives. and 399 r.w.h.p. 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. 0 Being lean, 0.5 being ideal and 1.0V being rich. 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. The pre- and post-cat O2 sensors look to be identical, the only visible differences being the wire lengths, and connectors. This cookie is set by GDPR Cookie Consent plugin. There is no difference between the pre and post O2 sensors. The lambda sensor is essentially two porous platinum electrodes. All Rights Reserved. Each vehicle may be different and require unique test Free shipping . The difference between the two is about $1,000.. please help all stuff is breaking this wknd !! By clicking Accept, you consent to the use of ALL the cookies. Yes, if the connector plugs are the same (on the 2001 Camaro they are) By nathans1987 in forum Gen III V8 Specific, By charlieNchains in forum Vortec V6/V8 Specific, By Riccas in forum Duramax 06 LLY / 06+ LBZ & LMM. If you need assistance having this checked or repaired, a qualified pro from YourMechanic can come to your location to inspect the system and replace any O2 sensors that are faulty. Your email address will not be published. 232/234 .595,.598 +2 comp cam with ported and polished stock heads with .650 lift dual springs and a bowl grind. The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. $71.24 . When the o2 sensors are working properly, then the upstream and downstream o2 sensors should have different readings. You just need to get one precat O2 sensor. Okay so essentially from my understanding, hopefully, someone chimes in. 1. Apply a clean and reusable pulse oximeter sensor to either foot. On the other side of the nernst cell, oxygen from the air outside the exhaust travels down the O2 sensor and makes contact. For a better experience, please enable JavaScript in your browser before proceeding. A4 (B5 Platform) Discussion. 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. for diagnostic use. Hover to zoom. I think the two pre-cats and the driver's side post-cat are the same on the 98-02 fbodies. For a better experience, please enable JavaScript in your browser before proceeding. Content on spyderchat.com is generated by its users. When the vehicle accelerates, the ECM allows overfuelling and ignores the lambda signals. 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. Training resources and demonstrations on PicoScope and the Automotive Diagnostics Kit. If you are going from Kingston to Cornwall, you are travelling downstream. This is due to the fact that bank 2 is representative of an engines #2 cylinder, while sensor 2 serves as a downstream designation. 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. Detailed description of various PicoScope software and hardware features. Since the oxygen sensor is in the exhaust stream, it can become contaminated. The ECU wont be able to adjust fuel trims properly. These can all affect the oxygen sensors response characteristics, resulting in an extended response time or a shift in the sensor voltage curve and in the long run reduced sensor performance. Upstream is before the Cat and downstream is after the cat. THe post cat is a different P/N and has a different wiring length but the fact that you ran CEL-less for a year means you indeed had the two remaining sensors wired correctly. Then use a spanner or dedicated O2 socket wrench - to unscrew the sensor from its seating. It does not store any personal data. 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. Tally how many spark plug wires are present. Disclaimer I think the passenger side one is a different part number because of longer wires. do i have to lower exhaust pipe ? functioning wise) Also, where can I buy a cheaper O2 sensor? The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Remember that bank 1 is determined by the side where cylinder number 1 is located. This enables the sensor to be located further away from the heat source at the manifold to a 'cleaner' location. The cookie is used to store the user consent for the cookies in the category "Other. Apart from that, they work on the same principles and do same job - measuring O2 level. 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 cookie is used to store the user consent for the cookies in the category "Analytics". PicoScope is the most simple yet complex tool in my workshop for diagnostic use. Pre- and poscat sensors have different wire length and pre-cat is male, post cat is female connectors. JavaScript is disabled. In an effort to diagnose the faulty component I have been monitoring the pre and post cat O2 sensors using the graph displays on the Torque OBD2 app, but I need some help understanding the readings. The information within is carefully checked and considered to be correct. A typical Zirconia lambda sensor has four wires. It lets you see what you previously had to guess was happening. hi guys i got old 02 sensor out a Little tight getting new one in. Cornbury House, Cotswold Business Village Check your VIN: I would be obliged if you could provide full bulletin, e-mail. Check engine light: whilst the check engine light can come on for many reasons, it is normally down to an emission related issue. Delphi Technologies is a brand of BorgWarner Inc. Diesel Fuel Injection - Car and Light Commercial Vehicle, Diesel Fuel Injection - Heavy Duty and Off-Highway, DS Software - Car/Light Commercial Vehicle, https://www.linkedin.com/showcase/delphi-technologies-aftermarket/, https://www.youtube.com/DelphiTechnologies. 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. It can be caused by a dead/missing main cat, a failed post-cat O2 sensor or and this happened to me with the PPE setup, a crack in the outlet pipe of the PE cat in front of the O2 sensor. Picture Information. 2,500 rpm engine speed. The Fora platform includes forum software by XenForo, http://www.realoem.com/bmw/showparts.do?model=ET37&mospid=47720&btnr=11_2181&hg=11&fg=50&hl=3, https://www.youtube.com/watch?v=21E5_u6dz0s, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. spyderchat.com is not in any way affiliated with Toyota Motor Corporation. Post-cat O2 sensors have much longer wires thus they cost a bit more. For a better experience, please enable JavaScript in your browser before proceeding. It is always going to be located after the catalytic converter. 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. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide. Other than the connector, is there a difference? Bank 2 Sensor 1 means Upstream Left/Front; Bank 1 Sensor 2 means Downstream Right/Rear; Bank 2 Sensor 2 means Downstream Left/Front. 2012 AUDI A6 (C7) 2.0L CAEB - PRE / POST CAT O2 OXYGEN LAMBDA PROBE SENSOR SET-2 . Maybe try a search? - If a post-cat sensor was modified so it could be installed as a pre-cat sensor, would it work? Switch on the oximeter and connect the applied probe to the oximeter. This website uses cookies to improve your experience while you navigate through the website. check out the. 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.