There is an AIRRADE intake on it with 3"downpipe going into 5" strait out the back so I think it's all good with getting air in and out.
The torque converter was rebuilt about 5,000 miles ago.
If the above are modifications(larger intake and exhaust capactiy for the engine) larger then what was stock?
If these increases were above stock more then likely even though these were added the engine might not be taking advantage of them.
There is a chance the PCM doesn't know these mods were made unless it can tell automatically somehow. Then the mods could be useless.
It may well be....and I say MAY that the diesel is saying so what! If the PCM doesn't know there is the capability of more flow
it can't take advantage of it, there is that possibility. The PCM,ECM whatever your manufacturer calls it MAY need reset to take
advanatage of the upgrade. I'm no truck expert to be sure. From experience I added an INJEN Powerflow intake system and a high flow
Corsa exhaust. I reset the PCM simply by pulling a fuse for 30 seconds and then drove it like I stold it after installing the fuse of course
so the engine could take advantage of the incresed in/out flow. Pulling the fuse in my case reset the PCM and logged increased in/out capability
when I drove it after the reset.
I'm no expert on diesel trucks for sure but I think it may be worth the time to look into that possibilty.
You need advice from a true truck (diesel) expert!