Ive recently replaced my full exhaust system. All parts were new apart from the manifold/cat and the lambda sensors that came with it.

I now have a CEL on. I can only assume its the lambda sensors. I tried getting the old ones off my broken manifold/cat but there rusted on there pretty damn good. Tried WD40 to loosen them but it hasnt worked very well. This said, I have a few questions...

1. The now fitted mani/cat is in OK condition, but the area surrounding the sensors is pretty rusted. Is there an easier option to getting them off without causing any damage to them so I can have them replaced?

2. And the pre-cat and post-cat sensors, are they the same? Do I just buy 2 of the same kind or do they differ in some way?

Any help appreciated

Thanks

Lee

you need to put a nice fitting spanner on the nut part then another big spanner onto the first spanner for extra leverage and they will undo
or a scaffold pole on the first spanner
weirdly i didnt realise but both lambdas do lok to have the same connecters on the end,i always assumed they were different

So leverage for the win lol! Ill give it another shot thanks.

Im aware the sensors sense the amount of oxygen in the exhaust fumes and tell the ECU the engine is running either lean or rich so it can adjust accordingly. How will this affect my engine/fuel economy if one or both of the sensors is faulty?

A better (safer?) bet is to either flag down the Snap-On truck and buy a special lambda socket or buy an impact socket (6 sided) and chop a slot in it just thick enough for the wires. They can be on very tight indeed. Plus Gas (or even deisel) will work much better than WD40.

I'll check that out Fingers99. Cheers for the advice lads

Also a few taps with a small hammer around were the sensor goes in may help free it off, i think halfrauds will do the socket.