2011 2.7 5 speed 4x4 P0302

This is a strange one. I had a MAF error code, replaced it. I then got O2 sensor codes, replace upstream and downstream sensors. Completed drive cycles to let the ECU learn. Now I get a missfire on cylinder #2(P0302). I have reset the ECU and let it learn twice, each time it runs OK until the drive cycle completes, then it reproduces the P0302. The reason I don't think it's an injector or coil is that it does not misfire until the drive cycle completes. Any clues to point me in the right direction? I don't want to throw parts at it. I have no vacuum leaks and no frayed or bare or disconnected wires anywhere.

 

Weird. I'd say it sounds like a vacuum leak but if you're sure there isn't one then I'm not sure. Hope someone else has some more insight for you!

 

I was thinking that the MAF sensor could be new, but faulty. I didn't have a Denso available, so I ordered an off-brand replacement, which may have been wasted money. It doesn't throw a MAF sensor code, now, but I guess I need to check fuel trims to see.

 

Sensors that affect the whole engine rarely cause a single cylinder misfire code to set.

Try this; swap the spark plug from #2 into #4, the injector from #2 into #3, and the coil from #2 into #1. If the misfire code changes to one of those other cylinders you'll know what's faulty.

If the misfire code stays on #2, something else is afoot.

Report back with your findings.