Threw a p0172 on the way back and on a slight Hill couldn't go over 30mph. I unplugged the front O2 sensor and no change. Now my girlfriend would fill the truck up to where the gas was right below the gas cap, because she got tired of stopping for gas (this problem can cause crap mileage). Now I'm thinking it might be the charcoal canister, or maybe the map sensor.

Do they even make replacement charcoal canisters for these trucks?

 

The charcoal canister can be flooded by topping off too much but I don't know if it would cause a rich condition. You can just disconnect the purge solenoid which would obviously cause EVAP DTCs but seals off the canister from the intake. Thinking of it, check the purge solenoid for proper operation because if it's stuck open it can cause all sorts of drivability issues.

 

Code is for bank one, P0172 1/1 Fuel System Rich. You have 4 or 2 02's?

 

I had similar issues when my camshaft position sensor (pickup coil to the parts counter guys) was on its way out, the engine was acting like it had no power and was bucking then if I shut it off I couldn't start it again until it cooled down.
I would test the injectors since they're out in the open and easy to check, my old camaro had two bad injectors and it had a big time running issue with 1/3 of them not squirting like they should.

 

I'm going to try that today if it acts up. Fuel trims were maxed out when this was going on
2 O2s
I'll throw that sensor on the scope and check it out

 

I know these gas tanks are supposed to be "vented." However, if the purge system is **** up or the tank is developing a vacuum above the remaining fuel as it drains out, it can cause a very gradual/insidious fuel starvation issue. The easiest way to see if that's the problem is to leave the gas cap off n see if the problem subsides.

 

I tried that to didn't work I also listened to see if air escaped when opening the gas cap.

 

So my next strategy is it wait until it starts acting up and try unplugging the purge solenoid. I'm ohming it the injectors tomorrow to see if one is bad. I don't believe it's the crank sensor but I did see a small spike in the graph. To my eyes it's nothing but it could be something. Cam sensor had the same spike at the same time to, which I find weird.

It does have a rough idle

 

Did you see what the temp does? Staying to low will tell the pcm to feed more fuel thinking it cold.

 

Yes sorry thought I included that. The temps were pretty spot on. Coolant temp matched the radiator. The IAT seemed to be normal to.