I bought a truck finally!! Yea!! its a 2003 5.7L HEMI, guy I bought from said the engine got damaged shortly after him getting it, he then was able to pick up another 5.7L HEMI but it was out of a 2005, but the mechanic did the "general install" and it runs, but there is a sensor at the front of the motor that is not plugged in and there is no harness to connect to it either. The check engine light is on, the electronic throttle light is on, and the truck does not shift into overdrive. Sounds like it's in total limp home mode. Can anyone help me out so I can get this truck sorted out and running right, I want to DRIVE it, but it's sitting because I want to fix it first before damaging anything. ANY help is MUCH appreciated.

 

It does sound like it is in limp mode but you need to describe more accurately where and what this suensor is on the front of the block because there are several ranging from cam positioning sensor, oil press sensor, EGR (on an 05 but not an 03), ECT.

If nothing else, take some pics and post them.

Do you have any CEL on or had the trucks computer scanned for DTCs?

 

I scanned the PCM, and it came up P0129 which is a MAP sensor type code, I went to Dodge picked one up installed it, cleared the code and WALLA!! truck runs right now!! I also found that this motor I have is a 05 with EGR, but it still has the 03 harness (twin PCM/TCM computers) where the 05 has a single PCM. The 03 does not have a wire for the EGR sensor, I guess 03 did not have EGR? I assume it's ok to run without the EGR hooked up to anything? do I need to block it off or remove it??

 

Im not sure what blocking the EGR in our trucks would do as far as damage but in my Supra it causes overheating issues in the rear of the engine. If you do block it off please monitor your temp very carefully and check your fluids often.

 

You are correct, the 03's did not have EGRs. Some guys do block off thier EGR's and claim better performance while others claim it is at the cost of MPG's. They do make block off plates but i would leave it as is as long as you are not getting any CEL's from it. The only thing that is likely keeping that from happening is your 03 PCM and wiring harness because your PCM never knew it was supposed to have one anyway.