It holds for all tunes.
The P0420 is a value in the computer. The tunes modify numerous values to increase performance. So this is just something you disable. Vince can do it.
Tell him you want the Cat Delete. Most GM tuners understand that means turn off P0420.
Actually, I was more interested in the additional horsepower! Does that hold true with the Trifecta tune? Would love an additional 25+ at the wheels. Our cars are registered in Florida so we skip the Nevada smog check BS.
Mine - '08 Brazen GXP. Trifecta tune, Magnaflow exhaust, DDM backbone and brace, rear Z0K sway bar, Eiback springs, debadged, 19" wheels.
Hers - '08 Bluestone Redline. GMPP tune, Magnaflow exhaust, DDM backbone, debadged (mostly). FOR SALE
Last edited by roadstersol; 02-05-2013 at 11:06 AM.