Any Idea?.....3406E Cat Problems

It wouldn't, couldn't. You have to break down the system into it's compnents and isolate the compnents that are independant of the cruise system and it has to be there. it can't be any of the shared systems.

I had a pete with a detroit that had harness problems for the three years we had it. Had it in the shop numerous times. finaly we sold it and sent it in for something or another before we delivered it and they found the problem that time. Talk about being mad.

 

Sounds to me like you have a ground problem. I would check ALL of the ground connections on the truck and engine, especially the engine compartment. A bad ground will make trucks, and cars for that matter, do a lot of crazy stuff. Just keep in mind that there may be 15 to 20 connections or so to check, depending on make and model. Also, don't rule out batteries. Since it was in an accident, it may have jarred the lead plates loose in the battery, and that can cause crazy things to happen. It definately sounds electrical to me, so I wouldn't spend anymore money on mechanical repairs until I knew for sure. Hope this helps.

 

I,m with you rodehound,every one of them sensors have their own gd,if ir's not tight they will send a false message to the ecm,the ecm says reduce power,and it can't because the ground is intermitten,you said the truck was in a wreck,but was it acollaison,or a rollover,or what,thats my opion,hope this helps.

 

they may have moved a wire while they replaced the ecm causing to to make it's connection then it loosened back up over time. I'd check every plug and conection within a few feet of the ecm

 

well i would definatly stop throwing parts at it and take it to a reputible shop with an excellent troubleshooter...be prepared to leave it for a few days with full tanks...have them hook up the scanner and take it for a 100 mile road test...preferavibly with a load...and over a big hill...alot of shops that have tow trucks also have an equipment trailer they could put a forklift or something heavy on to get the loaded condition...as alot of time sytems aren't severe enuff to notice empty (trust me)....definatly check all grounds and connections

at one shop i worked at we had a strait truck...blowing white smoke (unburnt fuel) out the pipes....computer said all was ok....good return flow...injector pulsewidth and coppers were good...pump pressure was within specs...little blow by...in short everything checked out normal...took us forever to figure out what was really the cuase....when we did it was something small and stupid

 

Was it replaced before it started acting up or was it replaced trying to cure the problem. Just because a part is new doesn'tmean it's good. I'vseen more problems from new parts than you would imagine. If it was replaced and then the problem started I'd geta new one to try. If it was replaced because of the problem then it may be a coincidence. I would imagine with it unpluged it would go into some sort of "limp" mode. Personally I'm surprised it runs with it unpluged.
If you have spent that much money at the cat shop mabey they would "lend" you another one to try so you don't have to pay for another one.