Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [lambda]

17 questions
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3 answers

Removing stubborn o2 sensor - danger of stripping thread?

(2002 Toyota Previa/Estima/Tarago ACR30, engine 2AZ-FE) One of my two pre-cat O2 sensors is faulty. The garage I put the car in did not manage to replace it - they told me it is stubborn and that even after applying heat (acetylene burner) it did…
MaSlo
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What causes narrowband O2 sensor behaviour?

It's a given that narrowband O2 sensor (Lambda) output swings up and down within the 0-0.9v range, but everywhere (on the 'net including here) I am seeing people say this is due to the ECU in closed loop in effect firing the injectors rich/lean…
Ian Cope
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Is there a chemical limitation to the mixture an engine can maintain?

I know that the question/title is a bit ambiguous, but I couldn't wrap it in a single sentence, so please let me elaborate. You can change the mixture of an engine for whatever reason. Because of multiple reasons, it's unwise to go either too lean…
Bart
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How much leaner can you responsibly run an old engine?

I've got a '76 Triumph TR7 and I was wondering this after I got its carbs tuned after its restoration. As many of you may know, old engines are initially not capable of running as lean as modern engines, due to less (local)cooling capacity, and…
Bart
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Does an oxygen sensor's lambda value represent the same when running on LPG?

I have converted my car to LPG, and i've been tuning it today with a wideband lambda controller. It runs pretty okay, but i'm not yet satisfied. The weird thing is, it accelerated best when the lambda value was tuned to about 0.78. That figure seems…
Bart
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Very high short term fuel trim

I was checking my short term fuel trim numbers and o2 sensor switching speed as I think my post-cat sensor has degraded. The car is not throwing a code, and I don't believe that there's a hole in the exhaust but I am open to correction. At both idle…
Nick
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2002 Toyota RAV4 major emissions issue, multiple sensor faults

I’m having problems with my Toyota RAV4. I bought the car 6 months ago with a lambda sensor fault. By time I got it home, had lambda bank 2, sensor 2 and Mass airflow sensor faults. Changed both, okay for 300 miles then had lambda sensor bank 2,…
LEP
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Lambda wiring diagram wrong from Bosch

I was sent a Bosch universal o2 downstream sensor however their wiring diagram does not match that of the original sensor lead which I need to chop onto. OEM is white, red, grey and black. Bosch part is white, white grey and black. Is there anyway I…
James
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Is my mixture too rich?

I've been running this single cyl scooter with this plug to about 30K KM (~19K miles). Replaced it today and it seems a bit dark. Is the engine's mixutre too rich? enter image description here
BlackNinja
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o2 sensor readings don't make sense to me

I get these readings as showed in the graph below from both o2 sensors and I am having a hard time to interpret them, especially sensor 2 (downstream). The readings are from a short drive around town (grey line = engine load). It's not throwing any…
Tim
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Bmw N52N Lambda probes madness

Owner of a BMW E60 523i LCI Automatic (N52N engine. aka N52k). 105000 Kms on the clock. The error codes below after deletion, re-appear after 300~400 Kms. It is theoritically impossible for 4 lambda probes to die in the same time. I logged some OBD…
Hanynowsky
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Driving without the second lambda sensor

I recently had a problem with the catalytic converter in my Nissan Pixo (UK Registration) and Mechanic told me to replace it. I usually buy original spare parts for my car from India as my car was made in India. I bought a new catalytic converter…
Mano Haran
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CO and Lambda fail after cleaner, air filter and throttle body clean

Went for an MOT, first test failed on high CO AND HC but normal lambda. Got new air filter, cleaned EGR and throttle body and added a cat cleaner into petrol tank. Second MOT failed due to high CO (nearly x2 as last time) and high lambda (1.037,…
LionLeon
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Procedure for measuring Lambda values at PUC Centres

What is the latest procedure of BS IV (Euro IV) petrol-engined cars in PUC Centres? As far as I know in Petrol Cars the car is kept idling without the Accelerator pressed, while in Diesel Cars the Accelerator is fully pressed. But recently PUC…
K Ghosh
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What formula is used when deriving AFR/lambda value from emissions?

When you get your vehicle hooked up to a gas analser, you'll see the 4 or 5 kinds of emissions you're interested in, and a lambda or AFR value derived from those emission values. I was wondering how the AFR is derived from those emissions. Surely it…
Bart
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