95LSdime

The truck is a 95 s10 5.3. For some reason it will run perfect up to a point then at random times when sitting in traffic or driving very slowly it will start to sputter and miss extremely badly to the point where it just wont run at all anymore and I smell a ton of unburnt gas. It will usually run fine if I drive it at light throttle but every time I accelerate hard or give it full throttle then come to a stop it will start sputtering and missing. So I changed the plugs and replaced the 02 sensors with 3 new sets and it makes no difference. It always seems to be the passenger side too. It starts to miss a little then it just gradually snowballs into a bunch of black clouds and hesitation. What do you think? Thanks

Here is the truck in question

95LSdime

Anyone?

LS1-450

iTrader: (33)

Check coil wires, coils, PCM to coil wires & injector fuses.

kmracer

iTrader: (1)

what do the other plugs look/smell like after you've run it?

crainholio

iTrader: (2)

Whip out your scan tool and post the Long Term Fuel Trims for both cylinder banks.

Then check the O2 sensor 1 for both banks while it's idling at operating temp, the mV should be bouncing around from >450mV to <450mV.

Let us know what you find.

DaveX

It could be an exhaust leak upstream of the 02 sensor. This would make the 02 "think" that bank was lean and the computer would compensate with excess fuel.