Only if you have a scanner that will check them.....

 

Nope don't have one of those.

 

Parts store scanner might do it. Wouldn't hurt to ask.... (they will usually do it for free as well.)

 

Ok I will check

 

P300 and P301 through P308 which are misfire codes. I can't figure out how the truck can be misfiring on all 8 cylinders and still idle smoothly. We changed the wires, cap, rotor and coil and then cleared the codes. After driving the truck for say 20 min the light comes back on. From what i was reading online it looks like the cat and 02 sensors will not change to the run position until the truck can run with with the light off for a set amount of time so I need to figure out what is causing the codes and the light to come on.

 

If your crank and cam aren't in cahoots, you'll set multiple misfires. I believe there is a data item on the scan tool for the cam/crank difference. If not, it will show up on "Set Sync Signal" in the factory scan tool or a high end aftermarket. Your monitors are not going to run when the misfire condition is there. The adaptive numerator must be finished before any of them will run and you also need to be between 1/4 and 3/4 tank of gas.

 

I didn't think the 96 PCM even cared about fuel level? I know the 98 and up do......

 

Well we are making progress. I replaced the TPS and got rid of six of the eight misfires. I now have a misfire on cylinders 6 and 8 only but i am done for the night, I will try something else tomorrow. if anyone has an idea where to go next let me know.

 

I would be tempted to do a compression or leakdown test......

 

Stuck valves will cause misfires as well.