Ksths2

iTrader: (1)

My c5 Vette had been acting weird lately, rough idle, surging really bad coming up to a stop light, but fine on the highway, anyway tonight all 4 plugs on the drivers side were super black and sooty, extremely rich, but the other 4 on paSS side were perfect, I put a new set of plugs in it and same thing in about 3 min worth of idle and driving time, I bought a new front o2 sensor and put it in but not sure if it fixed the problem yet as it just had ran in the garage for maybe 1 min but already seems better..... Oh btw, its not the coils cuz the temp gun said they all 8 were firing. And no lights or codes were on.........Any thoughts?

Ksths2

iTrader: (1)

Update: The new Bosch O2 fixed the problem, it ran the fastest 2 passes ever & all 8 plugs looked great. Only problem is it must of burnt up the new O2 already cuz its back to acting weird and the a/f says 9.6 on the passenger side (new O2) & 12.9 on the drivers side (old AC Delco O2)
One thing, I've been running 50-75% Sunoco 110 (leaded) fuel in it along with the normal 93 pump gas, I've read that fuel will burn up O2's is that what is going on????