I put a 4in turbo back exhaust with the 04.5 turbo elbow and now this code comes and goes. Usually its when I am on the petal accelerating. After a few starts of the truck it will clear itself. Is there a way to stop this code from coming up and should I be worried about it?

 

Any mods on the motor?

 

No mods other than the exhaust.

 

Bad/erratic MAP sensor. I had the same issue and coudn't understand how I could get an overboost code sitting in traffic or just starting the truck. My digital boost guage (reads off the MAP sensor) seemed to act normally but one day I saw it bounce for a fraction of a second. I found a great deal on a new one at Hoesli diesel and haven't had a problem since.

 

I 2nd a bad MAP/IAT sensor. They run about $160 from the dealer, but I'm sure Cummins carries them a little cheaper.

 

can you tell me where this Map/IAT sensor is and is it easy to change?

 

MAP sensor and IAT are 2 different sensors but I have found what I believe is the best deal at hoesli diesel for $66.00 (MAP sensor). This where I got mine and it fixed my problem with the P0234 code.

 

Where it the sensor located on the motor?

 

It is located behind the intake manifold and to the left of the fuel rail between all the fuel lines going to the engine. The first downward plug directly behind the intake manifold is the rail pressure sensor and it has a red or orange boot. The MAP is back a little farther and if you unclip it there is a blue water seal boot on it. It has four wires and one is blue. It is a little hard to get off but you can usually get your fingers around the fuel lines to get it unclipped. There are 2 small screws holding it down, so be careful you don't drop one of them down into the intake plenum when you are removing or installing a new one. Good Luck, Tom J.