# Cylinder 2 Misfire, need help...driving me nuts



## dsus4 (May 31, 2014)

2005 Sentra, 1.8.
Have a 302 error code, engine misfire on cylinder 2. Engine runs rough on idle, seems to run fine on the road.
At first I was thinking head gasket. Does not look like any oil and coolant are mixing, not loosing coolant, nothing milky or coolant smelly in the oil, no smoke etc from exhaust. Nothing off color on the oil fill cap. Removed radiator cap, started the engine from cold...no bubbles in the radiator. Heater is as hot as the sun and there is no overheating issue.

Replaced the plug. The coil has spark to it, but I swapped it out with a new one I had in the garage anyway. Swapped coils and plugs between cylinders, just to be sure. Put a new fuel injector in. I manually cleared the error code after each one of those, but the cylinder 2 error code came back each time.
Have sprayed carb cleaner all around the intake manifold while running with no engine response to indicate manifold gasket leak. Can't hear vacuum line leak anywhere, sprayed carb cleaner on vacuum lines to check anyway....no different engine response.

Did a compression test this morning. All cylinders are at 150 psi, they all pressurized the same when the engine was cranking...and held the pressure just the same as well.

What else could it be? O2 sensor? Would a bad O2 sensor only show on one cylinder and not have an O2 code thrown? Crank sensor maybe? No other codes were showing. How should I test for anything electrical on fuel and ignition systems? Seems if the cylinder is getting spark the electrical part is fine. There's fire in the cylinder, when I unplug the coil electrical harness, it goes even more haywire (rougher, engine more jumpy).

Any other ideas?


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## SPEEDO (Jun 9, 2003)

looks like you have done everything, have you checked for bad connections?


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