So my car had been sputtering a lil especially in first at low rpms. i changed the pugs and wires. Mechanic said it had a cylinder 3 misfire. and he changed the fuel injector. STILL SAME PROBLEM. He said it was going to be my valve adn it would be $1200.

But since he was wrong about the fuel injector being needed, and i wasted $220, Id rather run a diagnostic test to be sure that the fuel pressure isnt the problem (lilke the pump is going bad) or anything else.

Do u guys think those diagnostic test can pinpoint the problem? And how much do they cost cause i have no more money.