I just bought this truck last year. Ran great until earlier this week. I use it for work. But on to the problem. I was driving fine until i got to my next job and it started bogging in the parking lot. Its only on acceleration from stop. Once i get to second gear its a little bit better. I replaced plugs, wires, fuel filter, air filter and oil change. Didnt solve it. It runs better with the EGR vacuum line unplugged but really lacks some oomph. Can anybody direct me in the possible rifht direction?

 

Any OBD2 codes? I'd get the cats checked for blockage.

 

No codes thrown. I did check the cats and it is hotter like 590 before my drivers pre cat and cooler about 490 after that. 3-400 after post cat. With IR temp gun.

 

You need to check them for backpressure. A muffler shop can do that.

 

Sounds good. I'll have that checked. And I'll add that i have no cel/mil codes popped. Would a tps be another good place to check as well?

 

Hard to suggest what to check with no codes. That's why I suspect an exhaust blockage.

You could test the fuel pressure - there's a Schrader valve on the fuel rail, should be between 28 and 40 psi. Parts stores should have a gauge in their loaner tool kit.

 

Awesome! I was wanting to check the health of my fuel system. That will help me set my mind at ease. I appreciate it.

 

Okay confirmed clogged cats. I am going to replace them as soon as I can. Now would this explain that since it is getting hot here in Vegas that in the morning I seem to have more driving power compared to later in the day when it seems to struggle to get up to speed from a stop? this is a work truck with refrigeration equipment in the back, but I don't think the weight of my tools and refrigerant have anything to do with it... This week I'm also changing out my top end gaskets (head gaskets on up) I don't think this with the oil consumption has to do anything with this serious Lack of Powah either. Even thought I know the 4.2 isn't known for having a great deal of power. LOL

 

The oil consumption could be the cause of the clogged cats. If the rings or valve guides/seals are bad that needs to be addressed before you blow the money for new cats. There is a good chance that the motor is just worn out and that caused the cats to fail. Do a full wet/dry compression test before you rip into it, and a leak down test would be in order. Your problems may be bigger than you think.

Good luck