93 WRX.

There was a sensor of some sort after the cat on the downpipe. The de cat pipe does not have it.

What was it and is it ok to just leave it off?

Thanks.

 

Hi mate if this is the sensor after the little cat bulge then Mine has been chopped off. (Talking about the sensor of course). I have ahd no problems except my fault code is now showing an O2 sensor failure. No idea if this is the cause or if its coincidental. I am currently working on getting the GEms iengine management system so will dump the O2 sensor and the Maf sensor. Car is going well and getting some loud pops and bright flashes from exhaust

 

so you got a decat downpipe subtypr?
any good m8 and which make?

 

O2 sensor controls fuelling does it not?

Usually pretty important on most engines.

Does it not run rich or lean without it?

 

No sorry didnt explain myself very wellthe GEms is mapped with an o2 sensor only tells the engine if the mixture is correct for the cats in my understanding and if you havent got cats then why have the sensor. The Gems enginemanegemtn takes cqare of fueling completely and is setup using a o2 sensor but not required after setup.


The Downpipe is a magnex and is fantastic a def increase in power with the other bits and bobs and also a bit of increase in noise and also some good pops and bangs. No side effects either.