Ok I am trying to get my mustang to pass nys inspection, but it keeps throwing code P0306 cylinder 6 misfire. The car drives/idles fine, I cant detect any misfire when driving it normally or pushing it hard. After clearing out the code I swapped out the injectors, coil packs, and plugs to see if it would trigger a code for another cylinder. After about 20 min of driving the same code came back for cylinder 6. The car runs strong and I cant detect any loss of power. I am thinking maybe EGR ports are clogged? Just trying to decide what to try next??
EGR or PCV perhaps…
No real good info on google beyond what you have already tried…the only strange thing I read was a bad valve
Fords allow one code to be on when getting inspected. So you shouldn’t be failing. It doesn’t sound emissions based IMO
It doesn’t matter once the check engine light is on it won’t pass. I would confirm you have noid at the injector,power/ground at the coil,and compression on that cylinder.
Hows that plug look vs the others you took out?
Intake manifold leak?
Plugs all look fine, I pulled them all and #6 looked as good as the rest of them
cam lobe, follower, valve spring… compression, leak down, running compression comparison if electrically it’s functioning correctly. Interested to hear the result.
Make sure everything mechanically is in good condition. Check compression on all cylinders, if #6 is off by 15% from the others perform a leak down test. Once you have that data, it will be easier to diagnose whether it’s a mechanical or electrical problem.
Same code popping in my BMW. pain to diagnose thus far.
Just got done with the compression test , all eight were in the 90-110 psi range. Feeling better with those results. Still haven’t found my problem though.
Can’t figure this out, inspected in more detail the injector & coil connectors/wire and they look good. Cleared the DTC codes and P0306 popped up again.
You might need new coil “boots” (these are cheap to buy and easy to get.) If your problem still persist…its most likely your COP driver for Cyl # 6 in the PCM.
You try corral or one of the other mustang specific forums?
The coil packs are new, so the boots are new.
Yep posted up on corral, not much help there
If it can be PCV or EGR related could you have a leak in the system causing this? Smoke test for a leak?
I was thinking EGR because I found some info on the about ports in each cylinder that clogged up, but then later verified that the 4.6 does not have these ports. If it was EGR/PCV related not sure why it would come up with #6 every time.