'08 4.8L Limp Mode under load Issue

[Montanagreenmachine]

Any time I really get on the gas, or the engine is under load I go into limp mode and the engine feels like I'm running on 5 cyl.

Sometimes the MIL flashes then goes out, other times the MIL flashes and stays on.

In every instance after I shut the engine off and restart, the car drives fine. Some times the MIL will still be on, other times it resets and is off.

I have pulled the codes and get the following:

0029CC CDKMD 0x29CC misfire, several cylinders

0029D2 CDKMD04 0x29D2 - Misfiring, Cylinder 6

0029CE CDKMD07 0X29CE - Misfiring, Cylinder 2

Parts replace in the last 12 months:
New Bosch plugs, new coil packs, all 4 cam pos. sensors, cleaned all 4 vanos solenoids.

My first guess was not enough fuel due to a clogged fuel filter. (in tank on this model).

Any other guesses?

Thanks!!

[ard]

My guess is that you have a air leak in the intake somewhere- a cracked hose, fitting, etc... - and this is causing the air/fuel ratio to be off. It only shows up when you are running WOT. At partial throttle it isn't enough to cause issues. Just a guess.

Can you look at your fuel trims? AKA 'short and long term adaptations'

[Montanagreenmachine]

Originally Posted by ard

My guess is that you have a air leak in the intake somewhere- a cracked hose, fitting, etc... - and this is causing the air/fuel ratio to be off. It only shows up when you are running WOT. At partial throttle it isn't enough to cause issues. Just a guess.

Can you look at your fuel trims? AKA 'short and long term adaptations'

Good thought. I checked the boot between the MAF and T.B. All is good there.

WOT does cause it every time, so does 3/4 throttle, or if in lower gear heading toward a slight incline causes it (more load).

I have Carly, so I assume I could data log it (fuel trims, etc.) but I'm not sure what I would be looking at. (bit outside my wheel house)