Quote Originally Posted by bluegtp91 View Post
It should because using an o2 simulator in any '01+ car screws with cat diagnostics and fuel trims.

I'm not talking about the converter failing here.

Also, try to add a little pipe inbetween the filter and the MAF, sometimes the filter bolted on the end of the MAF can skew MAF readings causing crap readouts and messing with the tune. Been there, done that.
Ok ill try that for sure...I have the filter attached directly to the maf