I need to test the output of the lambda probe since I suspect it is not working correctly. Can anyone tell me where about in the engine bay I can measure the lambda probe output from or even where the lambda probe is?

Alan

 

Alan,

It depends what model Impreza you have. On my MY99 STI Type-R the Lambda probe is on the exhaust downpipe by the turbo underneath the intercooler. Just follow your exhaust back from the engine until you see the probe with wires coming out.
Hope this helps,

Craig.

 

Alan,

Just replied to your other post as well. On a MY94 import the probe is in the exhaust manifold under the engine.

This can be easily seen if you look in & down from the drivers side. It's literally behind the drivers front wheel.

Regards

Johny.