Bad 02's?
 

O.K here is the problem, the car is not throwing any codes and drives fine around town. But under WOT it bucks bad. I thought I was just spinning and hooking on the street but I took it to the track and the first pass I was down 10mph. Fuel and oil pressure is consistent and everthing looked good. So I made one more pass, which was .3 faster and 2mph faster. These are the original 02's from 99 in the car. I was thinking that they are fouled out and that after I did a WOT blast to clean them out some that is why the car went faster. Also I am running leaded racing fuel. Opinions?

well the leaded fuel for sure will ding those o2s...

btw under wot it goes into open loop ignoring 02s...

Thanks, found a faulty plug wire.

Can't run leaded gas and still use front 02's. After half a tank the 02 sensors will become sluggish.

I've run about 25 galloons and had no problems untill now, but I think it was the wire. I ordered the Denso 02's just to be safe.