Assuming I use an O2 simulator on my post-cat O2 sensors, does anyone know how much more HP and TQ I'd get running cat bypasses and muffler as compared to 100 cell racing cats and muffler. This would be on a GT2. I'm not interested in 'shooting flames' but want best power without extreme noise. Anyone with any experience comparing the two?

 

I've heard that no one has gotten O2 simulator's to work on a 996. I have heard of ECU upgrades derived from an program from a non catalyst country that doesn't monitor the secondary O2 sensor.

 

contact Todd Knighton @ Protomotive. he can reprogram the ECU to work with no cats and no CEL.

 

I have cat by-passes on my car. I don't think I got any HP from it but my car did get louder and it shoots flames. I have a GIAC stage 4 from EVO, it does not have the O2 sensors disabled. They can't or won't do it, I just get a check engine light about every 500 miles.

 

Orli930

Thank-you that is exactly the info I needed!