well I have a gen5 lude with a greddy turbo. I just had my downpipe and piping from the cat to the muffler upgraded to 3". the problem is I can't find a 3" cat thats good for an OBD2. I'm still running the stock cat, and I don't want to run a test pipe because of the damn Cali cops.

soon Ill be getting the AEM EMS, so I'm not sure if I will need an ODB2 cat at all. does the AEM EMS use the second O2 sensor as well? or just a wide band in front of the cat?

would you guys suggest getting a 3" cat used for OBD1 and installing a bung at the output for my second O2? or do I just get one of those O2 dummys I read that people use for the test pipes?

the guy at the exhaust shop mentioned that if I do that now, it may mess up the signals going to my OBD2, and thus cause some issues with my EGR. I had my doubts about this, but I don't really know too much about how the emmisions crap really works, so I figured I'd ask you guys.

any suggestions would be great.

 

anyone?