Help Needed - Emissions

facade

Take it back to the first place with the emissions print out, and see what they say.


They likely changed the sensor to get the fault codes to clear in the first place.




Lambda is a measure of the air:fuel ratio, the first sensor (pre-catalyst) adjusts the fueling to get the lambda to 1.000 before the catalyst. Any air that gets into the exhaust after this sensor will increase the lambda reading at the tailpipe, but the engine is running perfectly.


I don't really see why lambda is in the MOT, but someone decided that it should be, and it is.




Trouble with garages is they do what you tell them.



If you said to sort the check engine light, then they have.

If you said to sort it so it will pass MOT emissions, they haven't.
It doesn't take much of a leak (usually at a joint) to fail the lambda measurement.


I'd let them sort the leak now, and then find another garage for next time.

reddwarf2002

People are thinking the original garage fixed the issue, but looking at OP's post they did state the light didn't go out after the lambda sensor was replaced. The garage was also unable to find any fault codes for the MIL.

When the MIL light is on there is always an error code stored. Perhaps the garage didn't have a diagnostic tool capable of reading all the modules in the car otherwise there would have been a code.

My advise is to take it to a specialist who has the right diagnostic tools to read the error code. Without it you will be throwing money at it.

justtheonce

Thank you ...appreciate your time and info