Originally Posted by flnative70
Yes. They scoped the CMP and CKP wave forms at the PCM connector. Any idea where mismatched head theory came from?
Not really. I'm unaware of any substantial changes to the 4.7l over the 10 years it's been in use. I've done a few head gaskets on them; They all looked the same to me.
Your symptoms definitely match the codes; the computer seeing an incorrect CMP signal or none at all, and so is substituting an estimated value based on CKP input to keep the thing running. But when they do that, they retard the crap out of the timing. So yeah, it's in limp mode.
Did they verify the physical timing of the cam? You have to pop a valve cover to do so. That's where I'd be at this point.