05 CTS V 07 ESCALADE
Rumor has it that the Hi Flo cats that have low cell counts (200-300) can cause the exhaust to emit smoke when they heat up. I've had a few folks tell me that on track days the see some light colored smoke coming out the back at high rpms. Usually later in the day. We've never been able to find the cause. No head gasket or oil issues present. I've had this issue before and after engine mods. The only common denominator is the exhaust system (Corsa with Hi-Flo cats). Anyone experience this?