I'm now starting to throw occasional P0420 codes after running a little race gas mix (2 gallons Q16 to about a little over 1/4 tank). Its been a little over a week now...what are the effects of of race gas on the O2 sensors?
I'm running a DC DP with cat delete and my secondary O2 is screwed directly in the midpipe...I was thinking about trying the antifoulers but I've had the car for almost a year driving like this and never once got this code until I did the mix.
Any thoughts?

 

Leaded gas kills o2 sensors. It's a fact, there's quite a bit of info about it on EvoM too.

 

Thanks for the reply, I guess I'm a little surprised that just 1 night of racing killed the sensor already...since I live in Jamaica and we don't do emission tests, I think my best bet is to disable the rear O2 with Mr. Fred's patch.

 

or just try and back it out with the anti-fouler.

 

Disabling the rear o2 with the periphery bits will take care of the rear o2 perfectly.

Running the car a bit leaner in your idle/cruise areas will increase egt's a tad and keep the front o2 much happier.

The key to keeping o2's alive a little longer with leaded fuel is heat. You can't keep them alive forever, but it will certainly double there lifetime. The rear o2 is too far back,,, it will never be 'warm' enough to dispell the leaded fuel.

I hope this helps!!

 

Yea I'm going to try and put in a couple antifoulers and see if that helps, worst case I'll just disable it. So should my front O2 be alright for the occasional weekend runs on Q16 since it gets the most heat up there?? I know the time frame is relative but as long as its not anywhere near as fast as the rear ones I'm cool