I'm trying to identify and replace the Lambda sensor having almost failed MOT due to emissions. I figure even if it's not the Lambda sensor I should be able to make up the cost in increased fuel economy, then worry about the cat next year.
I can find what looks exactly like a 1 wire Lambda sensor sticking out the top of the exhaust manifold.
However, all the sensors listed on the internet for the Sirion (all models) are the 4 wire type, I've also noticed one of the parts is listed as "post cat". Should I be looking for another sensor after the cat? and ignore the what I've identified. Or go with what I've found and replace it with a 1 wire sensor?
If anyone can point me to the correct location of the Lambda sensor it would be greatly appreciated.
car in question:
Sirion Plus 1.0l 1999 model.