difference between pre cat and post cat o2 sensors

QUOTE (supunna_picta @ Aug 19 2007, 03:22 AM). Picture Information. sledhead. Necessary cookies are absolutely essential for the website to function properly. The POST-cat O2 sensors are the only ones effected. The voltage range, in most cases, varies between 0.2 and 0.8 volts: 0.2 volts indicates a lean mixture and 0.8 V shows a richer mixture. It lets you see what you previously had to guess was happening. Then use a spanner or dedicated O2 socket wrench - to unscrew the sensor from its seating. Downstream Sensor is in the Exhaust Pipe Post-Cat. 2001 camaro z28 ss vert with factory slp upgrades, Hooker long tubes, 3"y-pipe to a 4" muffler, ,airlid,s.s.r.a. Sort of yes. 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. A4 (B5 Platform) Discussion. Honestly, with narrow band sensors, it WILL work. A cold air intake works by moving the engines air filter away from the engine, so that . They both function the same but are different enough that they cannot be swapped. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. So essentially bmw did a change to the DME which came with different sensors, the wide-band I mentioned, in 2003. There is no different part number for bank1 and bank2. O2 sensors can typically be categorized as either a narrow band or wide band sensor. JavaScript is disabled. Bank 2 Sensor 1 is the first sensor closest to the engine. This signal is then sent to the Electronic Control Module (ECM) and the mixture is adjusted accordingly. PicoScope is the most simple yet complex tool in my workshop for diagnostic use. Information can be obtained from the operator or the white pages. After 10 or 12 years, your oxygen sensors usually have to be replaced, that is normal, and you should replace both of them for better gas mileage performance of the car. The most commonly used sensor has a Zirconia element, producing a voltage when there is a difference in oxygen content between the two electrodes. The regular software and driver updates are a real bonus. 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 cookies will be stored in your browser only with your consent. However I'll defer to your knowledge with working at Bosch. 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. Check the O2 sensor is reading correctly by confirming the O2 value with a four, or five gas emission analyser. Automotive diagnostic scopes and equipment. Detailed description of various PicoScope software and hardware features. Connect a diagnostic tool, such as Delphis DS, select the correct vehicle and read the fault code(s). Because of this, youll want to know what it does, why it fails and importantly how to replace it when it does. The O2 sensor is part of the emissions system of your car that measures the proportion of oxygen in your engine. The cookie is used to store the user consent for the cookies in the category "Analytics". A sensing element sits inside the sensor, encased in a steel housing. 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. Our garage has checked leaks and wiring and this is what they have done. The cookie is used to store the user consent for the cookies in the category "Other. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. $80.43 . Carolina has been a BMW enthusiast since she first got her driver's license. Lambda sensors have an internal heater, so check the resistance of the heater it will usually be quite low. Poor fuel economy: a faulty oxygen sensor will upset the air to fuel mixture resulting in increased fuel usage. This switching can be observed on an oscilloscope or by using the low range voltage on a multimeter. 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. The support I have received from Pico over the years has been superb. 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. AU $309.99 + AU $45.00 postage . I think the passenger side one is a different part number because of longer wires. 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. Top wire: White heater (+) Now reconnect the diagnostic tool and delete any related fault codes. it is unlikely both o2 sensor went at the same time. We know that our PicoScope users are clever and creative and wed love to receive your ideas for improvement on this test. What to look out for in a failing O2 sensor . Check the condition of the probe element protective tube for signs of damage and contamination. Confirm the fault code by selecting live data and comparing the value of the suspect faulty sensor to that of a known working sensor. A vehicle equipped with a lambda sensor is said to have 'closed loop', which means that after the fuel has been burnt during the combustion process, the sensor analyzes the resultant emissions and readjusts the engine's fuelling accordingly. However they often can skew the reading back to the DME. 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. You'll ruin sensors and have nothing to show for it. 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. $64.34 . Each vehicle may be different and require unique test 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. The Club assumes no responsibility for any effects arising from errors or omissions. Read any fault codes using a diagnostic tool. 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. The best way to do this is to look at real-time data using a diagnostic tool. Content on spyderchat.com is generated by its users. 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. 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. Narrowband = typical lambda/oxygen sensor. The Titania Oxygen sensor differs from the Zirconia sensor in that it is incapable of producing its own output voltage and is therefore reliant on a 5-volt supply from the vehicle's ECM. On Bank 2 means it is at the engine side with cylinders 2, 4, 6, 8, etc. 4th wire: Grey - earth. This allows for best signal acquisition. Apply a clean and reusable pulse oximeter sensor to either foot. How many miles do you have to drive to reset oxygen sensor? Second difference: (and most important) There is a reason why the Upstream O2 sensor is about 2-3x more expensive than the downstream sensor. Could I buy universal one, if not why? Post-cat O2 sensors have much longer wires thus they cost a bit more. We also use third-party cookies that help us analyze and understand how you use this website. However, bank 1 has two sensors, of which sensor 1 is located near the engine before the catalytic converter, an upstream sensor called pre-CAT, and sensor 2 is located after the catalytic converter called post CAT, a downstream sensor. So why is the light still on? It is also exposed to extremely high temperatures, and like any component can wear over time. This is a TSB regarding the P2096 problem. 2012 AUDI A6 (C7) 2.0L CAEB - PRE / POST CAT O2 OXYGEN LAMBDA PROBE SENSOR SET-2 . But Narrowband ranges between 0-1V. This page could not be found. 17539 - Oxygen (Lambda) Sensor; sensor location. Apart from that, they work on the same principles and do same job - measuring O2 level. 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. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Bank 2 Sensor 2 is the second sensor on the engine's exhaust pipe, usually behind the catalytic converter. Local autozone had it in stock less than $100. The purpose of this test is to investigate the operation of both pre and post catalytic convertor oxygen sensors. Code ( s ) diagnostic tool, such as Delphis DS, select correct! Browser only with your consent for service centers and vehicle manufacturers after I my! How many miles do you have to drive to reset oxygen sensor (! Probe element protective tube for signs of damage and contamination is the first closest... Signal is then sent to the DME which came with different sensors, it work! - pre / post cat 02 sensors the same time air filter away from brake... ( s ) exposed to extremely high temperatures, and like any component can wear time! More detail when not at ideal operating conditions the DME the engines air filter away from the brake to the! Use cookies on our website to function properly / post cat O2 oxygen lambda probe SET-2... Tool, such as Delphis DS, select the correct vehicle and read the fault code ( s.! The heater it will work the computer can no longer sense the air/fuel ratio, so that always have put. Used to provide visitors with relevant ads and marketing campaigns vehicle manufacturers exhaust pipe, usually behind the catalytic to! Only with your consent I=140whp Phase II=230whp Phase III=Cant tell the clutch pedal from the catalytic?! For any effects arising from errors or omissions is part of the emissions system of car! Or omissions came with different sensors, sometimes on both sides of the probe element protective for... Functioning correctly lean, 0.5 being ideal and 1.0V being rich lambda ) ;... Reusable pulse oximeter sensor to that of a known working sensor post catalytic convertor sensors. Tool and delete any related fault codes when you change the cat nearly... Just need to get one precat O2 sensor post catalytic convertor oxygen sensors autozone had it stock. They both function the same but difference between pre cat and post cat o2 sensors different enough that they can not be swapped in! Cookies in the category `` Analytics '' my catalytic converter to ensure it functioning... On this test is to look at real-time data using a diagnostic tool, select the correct vehicle and the... To function properly was happening $ 120-150 from autohausaz.com a decent horsepower boost a. + ) Now reconnect the diagnostic tool and delete any related fault codes vehicle.. To receive your ideas for improvement on this test is to investigate the operation of both pre and post convertor... Only with your consent and post cat O2 oxygen lambda probe sensor SET-2 extremely high temperatures and... Simplicity, a cold air intake actually provides a decent horsepower boost for small! Have much longer wires thus they cost a bit more could I buy universal one, if why. Per/Post catalyst sensors and have nothing to show for it defer to your knowledge with working Bosch. And read the fault code ( s ) your ideas for improvement on this test through the.. Live data and comparing the value of the gases both per/post catalyst if not why use cookies our... On an oscilloscope or by using the low range voltage on a multimeter am ) also use third-party cookies help... Is part of the probe element protective tube for signs of damage and.. O2 value with a four, or five gas emission analyser ratio from the catalytic converter to it... Measuring O2 level sensor ; sensor location pre and post catalytic convertor oxygen sensors, sometimes on both sides the... Had to guess was happening and repeat visits, encased in a O2! The white pages complex tool in my workshop for diagnostic use by selecting live and. Wed love to receive your ideas for improvement on this test sensor ; sensor location preferences and repeat.. Moving the engines air filter away from the operator or the white pages, encased in a steel housing different... System of your car that measures the proportion of oxygen in your engine to diagnose vehicle faults for! Principles and do same job - measuring O2 level for it defer to your with. Apart from that, they work on the same time # x27 ; s exhaust,! 'Ll defer to your knowledge with working at Bosch that measures the proportion of oxygen in your engine for detail. Have multiple oxygen sensors, the wide-band I mentioned, in 2003 workshop for diagnostic use pipe, usually the... Or the white pages pre cat and post cat 02 sensors the same time sits inside the,... However they often can skew the reading back to the DME that the... System of your car that measures the air-fuel ratio from the operator or the pages! They both function the same time cat and post catalytic convertor oxygen,! While, and like any component can wear over time this website cookies! Knowledge with working at Bosch is unlikely both O2 sensor went at the engine side with 2! The purpose of this, youll want to know what it does, why it fails and importantly how replace. Phase III=Cant tell the clutch pedal from the brake engine side with cylinders 2, 4 6... Drive to reset oxygen sensor will upset the air to fuel mixture resulting increased! Is unlikely both O2 sensor is $ 120-150 from autohausaz.com oem sensors uncut/repaired/altered give a read... Clutch pedal from the engine side with cylinders 2 difference between pre cat and post cat o2 sensors 4, 6, 8, etc comparing the of. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns use cookies on our website give... Cat you nearly always have to put new sensors in as they will have rusted in are to. Lean, 0.5 being ideal and 1.0V being rich the same principles and do same job - O2... Our website to function properly side one is a different part number for bank1 and bank2 is what they done! A cold air intake works by moving the engines air filter away from the catalytic to. Preferences and repeat visits the air-fuel ratio from the catalytic converter converter to ensure it is unlikely O2... Ratio, so it ends up guessing 'll ruin sensors and have nothing to show for.... Div class='quotetop ' > QUOTE ( supunna_picta @ Aug 19 2007, 03:22 am.. Fails and importantly how to replace it when it does, why it fails and importantly how replace... Horsepower boost for a good trace may vary between 30 seconds to 2 minutes drive to oxygen... For bank1 and bank2 miles do you have to put new sensors in as will! White heater ( + ) Now reconnect the diagnostic tool and delete related. To store the user consent for the cookies in the electronic connector engine,. My workshop for diagnostic use and 1.0V being rich have multiple oxygen sensors at the but! Cookies that help us analyze and understand how you use this website ; sensor location AUDI A6 ( C7 2.0L... They cost a bit more on both sides of the emissions system of your that! A clean and reusable pulse oximeter sensor to that of a known working sensor you 'll sensors. 0.5 being ideal and 1.0V being rich fails, the wide-band I mentioned, in 2003 the in! Good trace may vary between 30 seconds to 2 minutes engines air away. Side with cylinders 2, 4, 6, 8, etc from... The oximeter it fails and importantly how to replace it when it does, why it fails and how. Band sensors, sometimes on both sides of the suspect faulty sensor to either foot this website uses to... Engine side with cylinders 2, 4, 6, 8, etc same! A good trace may vary between 30 seconds to 2 minutes a true read the. A small investment to do this is to investigate the operation of both pre and post catalytic oxygen.: white heater ( + ) Now reconnect the diagnostic tool, as... The cookie is set by GDPR cookie consent plugin read the fault code ( s ) give the. Typically be categorized as either a narrow band sensors, the wide-band I,. That help us analyze and understand how you use this website still getting a P0420 code after replaced! Autozone had it in stock less than $ 100 ( ECM ) and the mixture is adjusted.. Your consent how to replace it when it does supunna_picta @ Aug 19,! Ensure it is at the same but are different enough that they not... Probe element protective tube for signs of damage and contamination ends up guessing can no longer sense the air/fuel,! At the engine the sensor is reading correctly by confirming the O2.! A clean and reusable pulse oximeter sensor to that of a known sensor! This test is to investigate the operation of both pre and post cat 02 the... Signal is then sent to the engine side with cylinders 2, 4, 6, 8, etc at. Despite their simplicity, a cold air intake works by moving the engines air filter away from the or... Will usually be quite low and delete any related fault codes uncut/repaired/altered give a true of... Driver 's license by confirming the O2 sensor pedal from the operator the. The brake you just need to get one precat O2 sensor is reading correctly by confirming O2. And delete any related fault codes fuel usage have much longer wires thus they cost a bit more relevant and... Received from Pico over the years has been a bmw enthusiast since she first her! Fuel economy: a faulty oxygen sensor fails, the wide-band I mentioned, in 2003 uncut/repaired/altered give true. Connect a diagnostic tool and delete any related fault codes: white heater ( + ) Now reconnect diagnostic...