Hi,

My MY99 impreza turbo has failed its emissions test and I need to replace the exhaust with the original one (which I have). The original downpipe that I have hasn't got a lambda sensor in it. The question I'm asking is will the Lambda sensor in the H&S down pipe high flow cat fit in the orginal down pipe hole or will I have to buy a new one? Without getting the car on a lift I can't see if the hole is the same size.

Cheers in advance?

 

Welcome. The lambda boss is a standard size so the sensor currently in your H&S downpipe should fit straight into the OE catted one.

 

Thanks for the reply.

I thought it was standard but size but on the original exhaust I was given there is no nut for the sensor to screw in to (even thought its in the exhaust) like on the H&S pipe that is on. I've attached a few photos of the orginal exhaust complete with lambda sensor fitted that I was given when I bought the car, I'm not convinced the exhaust is from the correct year or even an impreza.

Side view



Sensor



Sensor connection



Top



Top view


Cheers

 

The sensor showing on your photos is an Exhaust Gas Temp (EGT) sensor (cat on fire) so the downpipe is probably off an early JDM import impreza.

The O2 sensor for this model would have been in the RH manifold just B4 the up pipe.

 

Cheers, I thought it wasn't the correct pipe, bollocks