I think I may have found the problem. I pulled all of the spark plugs off yesterday and all but 3 or 4 seemed to be fouled. The ones that looked to be fouled were black and oily looking with carbon and crystalized junk all over them. Which I think is weird because they've only been on there about 30,000 miles. Anyone think thats the problem with the engine.

 

I would think that the fouled plugs are the result of another problem...

 

What about leaky valve seals or head gasket?

 

Could be valve seals, but a head gasket would probably only affect 1 or 2 plugs. Were half of the plugs fouled, like 1 bank only (you mentioned that 3 or 4 looked OK). If it's 1 bank only, you may have a bad O2 sensor on that bank. The afore mentioned intake gaskets could result in fouled plugs also if the PCM is detecting the extra air and compensating by adding fuel.

 

Hhhmmmm that coul be it as well. The only plugs that looked to be fouled were 2 on the drive side( the front 2 cylinders, I don't know the numbers) and the second cylinder from the front of te engine on the passenger side. I did replace the spark plugs and it did run a hell of lot better but the engine seems to spit, sputter, shake, and even a little back fire when put under a load.

 

well un plug your maf sensor see if it runs any better, mine did that to me a few times when it would rain.... it would go lean on the wideband id pull over unplug it then it would run around 13.2 and then 10.5 (still ran like **** but better than lean..) plus it didnt just jump to rich when i unplugged it, it would mellow out the idle then when i drove it it would go rich

i dont know if its the right thing to do but it worked for me

 

Fuel pump. Its a thought

 

I don't know what it is. I've checked everything other than performaning a vacum check. The weird thing is it seems to run almost perfectly fine sometimes and then other it doesn't even want to run. I'm hopefully taking it a shop this week.

 

Finally found out what's wrong with the truck. Apparently my passenger side oxygen sensor is burnt up. The guy who looked at it said something about how many volts it was showing and it was extremely low and even sometimes showed that it wasn't working at all. He suggested I replace both sensors and put my stock thermostat back in and reset the computer and it should solve my problem. Also, he suggested that it would be a good idea to put my rear oxygen sensor back on the vehicle because the computer uses that one as well to manage the engine (air to fuel ratio etc) but I thought it had nothing to do with engine performance or monitoring. In other words it's just a tree hugger device to make you have it in there along with catalytic converters. Lastly he also said the exhaust gas temperature was a to low due to the low temperature thermostat and thats what caused the sensor to burn up because the heaters on the sensor were constanly running due to the exhaust temperature being to low. Anyone have any other suggestions or other knowledge would be greatly appreciated. As of now I'm going to replace the sensors in the front and put my stock thermostat back in and reset the computer.

 

The rear sensors are only to determine if your Cats are working. You don't need those.

Front sensors should regulate up and down on voltage. They should not be at 1 steady volt.