Hey scott I got this stupid truck that needs your mastermind. Pic not related.

GreaseMonkey19

Ok so heres the scoop. Its misfiring really bad.

2004 Chevy s10 Xtreme V6

Ok so heres the scoop. Its misfiring really bad. The customer brought in the truck because it started shaking really bad on the highway all of a sudden.

Pulled the codes and got a P0300 multiple cylinder misfire. I also got a couple codes for the manifold pressure circuit and a couple for stuff like the airbags.

With my very thorough investigation, I have found that cylinder 1 and 3 work fine, but the rest are misfiring. I have tested and verified I have spark and proper fuel pressure as well as compression for every cylinder. I replaced the plugs, dis cap, injectors, fuel filter, wires. I have also inspected the whole distributor to see if it was ok, it was. I have yet to tear the top half of the engine apart and check the cams or anything underneath the valve covers. Do you have any idea whats causing the misfire? I also used a power probe and checked the electrical, seems ok.

One thing I will note is that the customer got a total hack job done with replacing the intake gasket and Mr. Shade Tree left coolant inside the cylinders. I took out the plugs and shot it out by cranking it over. I dont know how long the cylinders had coolant inside them.