my check engine light is on and im getting a misfire code on 6 of my cylinders and a random misfire. the check engine light will flash at me when im accelerating like when im getting on the freeway. it only does it sometimes though. my gas gauge will stop working too and it will just start bouncing around for a while then it will start working.

It all started after my truck just died on me while i was driving so i replaced the crankshaft sensor, camshaft sensor, cap and rotor. The guy i get my parts from also gave me a new pcm too, since i just replaced it a few months be for, just for good measure. then it started right up and about 2 days later this all started happening. ive pulled all the plugs and checked them for signs of misfiring and they all look good except for i cant check #8 because its cross threaded. plan on fixing that this weekend and replacing all the plugs. the wires are only a couple of years old and they have been rerouted. I have also looked to see if there is any oil in the keg and there is not. i have even gone through all of the grounding too, a couple people told me that might be the prob.

Does anyone have any idea whats going on?

 

Your plenum is blown.

The crank sensor is probably a cheap duralast unit, that our trucks just don't like.... Go with standard motor products, or a dealer sensor. inspect the on thats in there, and see if it is getting whacked by the flexplate.

 

Its a mileage plus sensor from napa but that is prob not any better than a duralast is it? ill pull it out and check it though. will the sensor or the plenum cause the gas gauge to do that? I just went and checked the plenum again, got a mirror in there this time and its definitely bad. the truck is my daily driver, is it ok to keep driving it till the stuff gets here to fix it or should i park her? sorry for the stupid questions

 

Ans if your plenum is blown, your cat and front 02 sensor likely need attention. HeyYou would know better than I, but if you replaced PCM there is something about getting it flashed to your VIN?

 

I am sure they do. i am going to check them out in the morning. i plan on changing the thermostat too and might even consider changing the water pump and timing chain and gears too since im pulling so much apart already. the truck has 193000 miles on it so itll prob save me a head ache in the future. I would like to know if i need to get the pcm flashed though.

 

Gas gauge is an entirely separate problem. Probably the sender in the tank. Unfortunately, have to replace the whole unit, pump included.....

 

Start with a simple comp test before you spend any money or put any more time into the motor.