I hate to say it but when my neon was misfiring, my buddy worked at gm and got me a high pressure injecter flush, motor sounded like poop as it ran for 20 + minutes but ran considerably smoother after. Turned out that wasn't the cause of the miss, it was a burnt valve. Most jiffy lube type oil change places do the injecter flush, you can try there too. Obviously do the plugs wires etc first. Crappy tire in country hills is having a sale on ngk plug wires, just picked up a set for the yj 4.0l for $28.
Topic: fuel injector cleaning and testing (Read 1625 times)