1998 Chrysler Concorde State Emission Test Fail

Alberto’s Question: My 98 Concorde failed the state emissions test last week. It had the code for misfire on cylinder # 5. I changed out the spark plugs, the wires, and even the fuel injector on number five. Still won’t pass the test with the same misfire code. What am I missing?

Answer: Well, you covered the common problems for misfires on one cylinder. But of course, there can be many other causes–like a bad main computer, bad wiring, bad valve springs, or even a crack in the engine head. BUT, I was once bitten by a Concorde with the same problem as yours. I eventually fixed the car by replacing the intake manifold gasket. There was a TINY crack on the intake runner for the number five cylinder. I could only see it when I removed the intake manifold. There was carbon black around the crack where it had been leaking. SO, you might find someone with a smoke machine and see if they can smoke out a leak in the intake system. Since it’s misfiring on number five, pay close attention to the manifold gasket around number five.