whiteflash

Had to have been, I passed smog with no hiccups (minus having to vice clamp my oem cat to my header and my exhaust, but that's a whole other story).

Bossman302

Does anyone know if you turn off the secondary o2/p0420 code if it will still pass smog?

whiteflash

Last year I passed with my o2 sensor off; but then again, smog procedures changed last year (ecu reading only). So I can't be 100% that my experience is still relevant.

odb812

Short Story:

If you reflash your car back to stock before smog, drive it around on the highway to build up some data.

Long Story:

I reflashed my car back to stock and pretty much drove straight to the smog station and failed for not having enough data. The tech did all the other tests including putting it on the rollers and it passed for everything else, but it failed overall just for not having the data. I drove the car from SF to San Mateo and back, then SF to San Rafael and back and passed when I went back. In general, if you're going to be close, you want to drive on the highway right before smogging the car anyway to get the cat up to temp.

macr88

Readiness codes is I believe what they're called, the same thing happens when you clear a cel.

macr88

oh and my car passed with the Tune from blackTrax so no need to switch

odb812

Good to know, I'll try with my tune next time. I thought I was playing it safe going back to stock .

andrewhake

Cool!

macr88

As a note if you're running a test pipe when you tune be sure and enable the secondary o2 when you put the kitty cat back in as this will be disabled due to the test pipe during your tune. If < that is the case then you will need to drive a bit to clear the readiness codes since you'll be reflashing to enable that sensor.

MMisencik157

Same happened to me when I smogged my car last year. I swapped the stock cat/exhaust back in and disconnected my battery to reset the CEL. Drove to the smog place and failed for the same reason. He told me the magic number necessary to pass is 40 miles. Went on a drive and passed later that afternoon.