I just took the truck in to have a muffler delete made and I think the guy might have welded the pipe on w/o unhooking the battery... now my mileage is has gone down to 11mpg and there is a slight loss in power....

What could be the problem? Its not throwing any codes, except P2509, which is my fault be I tried to reset the pcm and I think I did it wrong... I removed the #41 (i think) fuse, put my seatbelt on, turned the key until I got a chime... I waited for ever for a second chime, but it never came... so what are the steps to reset the pcm??

 

Just a thought but maybe its because you removed the muffler. Those 2007 and newer dodges have a heck of an exhaust set up on them.

 

You probably mean on a 6.7... with all that emissions crap, I can understand, but not on a 5.9... but I could be wrong

 

Ya kind of a guess on my part. Hope its not to messed up. Looks like a nice truck. Was it a side job or an actual shop that did the work?

 

An actual shop... dude should have known better

 

07 5.9's dont have the funky exhaust on them. Did you watch them put the straight on your truck? i ask because most places torch weld exaust pipe so battery connection makes no difference.

my 2 cents

 

I would be very surprised if it had anything to do with welding. I have done quite a bit of welding on a vehicle with the battery still connected and had no issues. I did research on whether or not it would effect anything before I welded the first time and many people had encountered no issues.

The loss of power is possibly from the muffler delete.

 

Ive seen a_lot of ecm's get zapped on big trucks due to leaving the batt leads connected while welding.

 

it is easey to zap the ecm while welding instead of the so called welder hooking the ground clamp up to the pipe he is welding he hooks it on the frame , the pipe has rubber mounts so the current has to go through the engine and small ground wire to get back to the frame no more ecm

 

THAT is VERRRRRY interesting and could be a lifesaver ..... THANKS!

 

yea it is very common to zap an ecm. I work at a body shop and all of our insurance companies and i-car ( same as ASE but for body shop) require us to unhook batt. and even unhook all computer from vehicle when we weld. IF its possible. But at the least we HAVE TO DISCONNECT THE BATT.! So i agree on it possibley being ecm. my 2 cents