I have a 2001 dodge ram 1500 with a 5.9 it has 120,000 miles and its broke and nobody knows how to fix it, please help.
About a month ago it started getting real bad mpg and it doesn't seem to have as much power. I took it to a garage and they couldn't find out what was wrong, they checked the fuel pump and that's fine. One of the plug wires was lookin kinda bad so we replaced that and the guy at the shop said that's all he can see that's wrong and sent me on my way.
I put on a flowmaster exhaust about 3 weeks ago and it seems like that made the problem worse. Now just yesterday everything went down hill. It idles real rough (rpms bouncing all over the place) and sometimes it stalls out if your not on the gas. Whenever it shifts it slams into gear and whenever your on the gas its real choppy, you can hear it in the exhaust that its not smooth.
Ive checked every fluid, wire, etc. and everything looks fine, I don't know what else to do besides bring it back to a garage and risk paying a bill and it not being fixed again. If someone can figure this out I would be so grateful.

 

You probably need to start with the plenum, O2 sensor, and catalytic converter, and maybe a new set of spark plugs, and see how life gets after that.

May not be all of the problem, but probably accounts for a fair amount.

 

How much of the exhaust did you replace? Did you replace the cat?
Sounds like it could be plugged cat.

Dave

 

Sounds like the Cat is plugged or your cap and rotor are bad .

 

+1 on plenum and o2 also go ahead and clean up the IAC on the TB could be a contributing factor to the Idle

 

Cap and rotor are cheap and easy , be a good place to start in my opinion .

 

I would check to see if your computer has any codes stored. Sounds like an O2 sensor is bad and killed the spark plugs. Definetly check to see if any codes pop up though.

 

I just found out today that the problem is with the transmission and now I need a new one. Does anybody know where I can get a brand new transmission or maybe even a good rebuilt one? How much would a shop usually charge to do it for me?

 

What exactly is the problem and who said it was the transmission? Transmission rebuilds aren't cheap, so you need to be sure that's the problem before you go looking for transmissions...

 

Well the problem kept getting worse until I went to move the truck to shovel my driveway and it wouldn't move at all so I had it towed to a shop and when they drained the transmission fluid it was all burnt. Before they checked the fluid they went over every sensor and checked the things you guys told me about and told me for sure its the transmission. Not really the best news to find out on your lunch break in the middle of the woods. If I can I would like to get a tougher transmission since I do a lot of wood hauling with the truck. Im not looking to spend my life savings but I expect it to be a bunch of money.