I'll be the first to admit I don't know much about Toy's, did the usual search and didn't find much to help with my son's truck.

It has been running rough/missing for about 3-4 months now. Mostly notice it under load but never goes away completely. Mileage is crap as is power. Don't know how to pull the codes on the Toyota's so maybe someone could fill me in. Check Engine light is on, of course <img src="/forums/images/graemlins/smile.gif" alt="" />

Replaced plugs/wires/rotor/cap and O2 sensor. No change. Checked for vacuum leaks and none found.

Where should I look next?

<edit>miles are about 150k and do not know about timing belt time.