Whats up guys, just have a quick question in regards to running a catless set up and having to pass emissions. I had my trailblazer SS catless, and my tuner actually tricked my ECM to read resistance even though i didnt have cats, and i passed no problem. I originally had a trifect tune on my regal and had to uncheck my O2 sensors, however, my car recently went to ZZP and now i have HP Tuners. I havent thrown a code yet, but just wondering if i have to tell ZZP to tune them out (trick my ECM)... Im pretty sure if they straight turn them off i will fail because it will say not ready, correct?

 

no

 

My catless DP showed not ready. Had to install the cats and go back for inspection. Without a tune, though.

 

well that sucks....