If we could diagnose it over a computer, mechanics and doctors wouldn't be needed. The biggest part of their job is to diagnose the cause of a problem, then they spend a little time fixing it.

You need three things to get power from a cylinder, fuel / air, spark, and compression. Missing any of those creates a misfire that is detected by the Engine Computer. Replacing random parts is the most expensive and least effective way to diagnose this type of problem but to waste no money, switch two injectors to see if the misfire moves to a different cylinder. Chrysler has extremely little trouble with injectors but this test won't cost anything. Next, perform a compression test to look for a leaking valve.

Answered by caradiodoc (expert)
17,280 answers provided