Got 99 problems and my Gen 1 is 1

[Nex]

Have you looked at the IAC?

 

[2011reptar]

Have you looked at the IAC?

I looked at the throttle body and cleaned it. Throttle % in Forscan looks stable as well. Figures.

 

[Guardrail]

Have you checked for a cracked exhaust manifold or broken stud? My truck did weird stuff like that when I had a crack between the Number 6 and 7 cylinders.

 

[2011reptar]

Well, compression looks fine…

 

[2011reptar]

Have you checked for a cracked exhaust manifold or broken stud? My truck did weird stuff like that when I had a crack between the Number 6 and 7 cylinders.

I haven’t, but I will. I’m starting to think it’s exhaust related, also because that’s basically all that’s left aside from the ECU. It is hard to believe an exhaust issue would only affect one cylinder… but maybe the misfires I’m seeing are a red herring to the idle problem anyway. Could maybe be a slightly weaker valve spring on that cylinder or something so it’s the one showing misfires, I have no idea. It’s odd it doesn’t produce misfires at a high rate, even when replicating the shudder. 5-10 per minute is still well within normal spec.

I’m out of ideas though. I’m gonna try to get the 02 sensors off and replace them as well as bore scope the catalytic converters.

 

[MTF]

Just a little FYI, early 2011 had cam shaft issues and would start galling between lobes and rockers.

But like most suggest. unmetered air and/or exhaust leak, dirty MAF sensor and weak O2 sensors, weak battery, bad fuel and/or water in the tank, low octane, etc... will produce misfires.

A proper smoke test will expose any leaks once and for all.
I had it done when chasing down a too lean/rich condition, once the tech wiggled the Canister purge valve smoke was detected. The valve itself was good, but the O rings were not.