[silversleeper]

I didn't know they disabled the o2 on hp tuners, learn somethin new everday.
Yes they plug in and fail if there is any slightest change from stock tune, so as you might know no such thing as disable and pass. If you reflash your tune back and forth by the time you get enough smog things to say ready it will say cats fail if you don't have them. IDK if your halfcat setup will be good enough if you flash back, the second question how do you not get a cel if you go back to low perf cats will be trial and error.