I have a catless uppipe and downpipe installed in my '02 WRX. Recently I was getting a check engine light. Since I have a pretty good relationship with my local dealer I brought it in and had them check it out. Of course it was the rear 02 sensor, I believe the code read that the sensor itself was malfunctioning. They chose not to see the mods and replaced it under warrenty. That was very nice of them however the sensor they pulled off had a little resistor added on to it. Is this the "CEL fix" I need to prevent further errors? So far it hasn't given me a light. The tech who worked on my car said that any tamerping with the sensor can throw off the readings sent back because your only dealing with about a volt so reapplying the fix will eventually produce the same results. What other alternatives do I have to this fix? Is there an ECU modification I can do to prevent the light? Thanks for the help.

 

you can make a manuel fix like the PDE. i went to a muffler shop and had them weld a little bent pipe and a bung on the end of it. just look at the PDE and copy it.

 

get 2 spark plug non-foulers in 18mm size. enlarge the hole in one of them to be 1/2" diameter, and screw the 02 sensor into this. now screw that into the other non-fouler. install the whole thing where the 02 sensor goes. it moves the 02 sensor far enough out of the exhaust flow to think that everything is working fine.

 

Anyone know how much the O2 sensor is I think mine is burnt or something. I assume the subaru O2 sensor must be expensive is there a generic one that is just as good. I have an 04' WRX with PDE down and accesport stage 2 california.