Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com - View Single Post

FB3 · 06-19-2010, 12:50 PM

I have several concerns regarding these cat replacements. One, which has been mentioned, is the placement of the rear O2 sensor to fool the system.

The other, which I have also seen somewhere but have not seen any numbers, is what is the air fuel mixture with a stock ecm?

I am guessing that it will go pretty lean, especially with a cai system, and if the ecm cannot adequately adjust the mixture without a tune there is a real risk in valve and piston damage over the intermediate and long run.

Just my guess, but I would definitely have to see some dyno numbers before installing any high flow cats without a tune.

06-19-2010, 12:50 PM	#24
FB3 Drives: 2014 Camaro 2SS RS LS3, BRM, NPP Join Date: Apr 2010 Location: Miami, FL Posts: 411	I have several concerns regarding these cat replacements. One, which has been mentioned, is the placement of the rear O2 sensor to fool the system. The other, which I have also seen somewhere but have not seen any numbers, is what is the air fuel mixture with a stock ecm? I am guessing that it will go pretty lean, especially with a cai system, and if the ecm cannot adequately adjust the mixture without a tune there is a real risk in valve and piston damage over the intermediate and long run. Just my guess, but I would definitely have to see some dyno numbers before installing any high flow cats without a tune. __________________ Experience is the best teacher but the tuition is very high.