Hello,

I am back! I will first say, the truck made it to its final destination (3800 mile trip) peed out 8 quarts of oil through the leaking oil pan gasket, blew a valve stem lost our cats litter box and almost hit someone that cut us off!

Been here for over a week now and the truck has developed some issue that makes it undrivable. I believe It is related to the recent plenum kit I had installed.

symptoms: misfiring while idling, misses, hesitates and stumbles through driving range, cel flashes periodically.

Ruling out the ignition system; The plug wires look to be in good shape and are mopar brand, have tested resistance on them with known working one, tested the two offending spark plugs resistance and checked out.
Fuel system: swapped both offending injectors with non-offending cylinders (waiting for the cel to pop back, have only let it idle for about 30 minutes - no cel but still clearly an issue)
Compression: 150-160 on both cylinders
air: Looked down the tb to see if there was any oil/pooling but it looked clean. I am leaning towards the intake gasket failing since I had just installed it
My other thought was it could be a bad 02 sensor since it smells like its running lean, and had a sucking noise/low idle. But, am not convinced since this was already an issue before. Could the 02 sensor have failed even more?
I am ordering a leak down test to try to confirm before I remove the intake again. Could I spray some carb cleaner in the area to see?

 

If you have an external vacuum leak, spraying the carb cleaner around should find it.

I might try unplugging the front O2 sensor, and see if it runs any better.

What spark plugs do you have in it?

 

Pulled 02, no real change, sprayed carb cleaner down into the area of 1&3. Plugs in are autolite

 

Coppers?

What did they look like when you had them out?

 

they had a lot of brown/tan deposits. I had ran seafoam through the intake prior to the trip so this could contribute to that.

Don't think its the plugs since they are the same ones that just go me through the trip. I will swap them with two other cylinders that aren't giving me codes. I attached a picture of some plugs. center and far right were from the offending cylinders, the one on the far left is from cylinder 2

 

There appears to be some variety of fouling on the far right..... center actually looks pretty good, left looks like it may be running lean.....

 

So, I am not sure what this truck is doing. We needed to go to the store so we chugged and backfired our way to the store, the cel light came on indicating the same codes. Gassed up (it was on the red) and reset the codes. After that, all cel codes went away and we got home flawlessly. I proceeded to take it for a ride to see if the codes would come back but they didn't.

My only thought is that I could have bought bad gas.....

 

May not hurt to drain the tank, clean it out, then fill with fresh gas. All the crap tends to collect at the bottom..... especially.... water.

 

Is it a difficult job? Could I run some sort of cleaner through the tank?

 

Just running stuff thru it isn't nearly as effective as physically removing it, and cleaning it out. Difficult? Well.... it can be.... depends on how much rust there is. And wait until the tank is almost empty as well. Less weight. (this is why fuel pumps fail right after your fill the tank. It's a revenge thing. )