Okay. 1999 zx2 5-speed 168k. No AC, no power anything. I have been bothered by this issue since last summer. I had a bunch of work done on the car ($1000+) new clutch, slave, master, CPS, main seal, resurface flywheel. It came back with a misfire on 2 and 3 P0302, P0303 and sometimes P0300 blinky cel. I had this before, but plugs and wires eliminated it years ago. I had the mechanic go over the car twice to find it- fuel trims good, good battery, new high end alternator, backprobe crank sensor, everything good. No vacuum leaks that I know of. Head gasket is good. Put it on his Verus and drove it for a week and concluded it wasn't misfiring. I gave up and just drive it. Had a idler pulley grenade itself at 50 mph and threw the timing belt back in June. Had it towed to a shop (was at the coast for the weekend and left it). Guy put a timing belt on it new pulleys. He compression tested it, came out fine (non interference engine vin-3). Still misfire codes. I flushed the radiator last spring. Put new plug wires, new Motorcraft plugs (the right ones fine wire) a couple.months ago. Didn't change. I'm putting good quality gas in and did a bottle of Techron injector cleaner on a 1/4 tank and it seemed to run 'better' but still misfires. Doesn't run hot, never overheated. Car has idled rough for years, but otherwise car runs fine other than hesitation off the line sometimes (1st gear only), and it does lose power in 3rd gear when merging onto onramps, but that's random. I clear codes, but they just come back. Seem to happen consisteny off idle after sitting st a light, or in 3rd gear going uphill or on hard acceleration I can feel it missing but almost unnoticeable. The only things I can think of is a throttle position sensor, invisible vacuum leak (I fixed one with the PCV years ago- had it smoke tested), bad coil module. Engine burns hardly any oil (maybe 1/4 qt. between 4500 mile changes, I never have to add oil). I am at a complete loss! Any help is appreciated.