I have an '03 QC HEMI. When it was new, and after I unplugged the TCM, it would light the tires up all the way through second and never bog the engine. Now, I can barely get the tires to turn over while power braking. It seems that the engine just doesn't want to open up any more. I had this same problem on the '97 Ram I had with a 360 5.9L. What is causing this? The only mods I have are a Flowmaster and the TCM unplugged. The truck has 52000 miles on it now and my wife drives it most of the time. She does not baby it either. I have been a Dodge owner nearly all of my driving life and I know to own a Dodge you got to hang a foot in it to make it run right. If you don't blow it out often it will tend to get sluggish.
Recently to try to solve the problem I have removed the throttle body and cleaned it well to remove the build up on the blades, regular oil and filter change with Mobil 1, checked tire pressure (40 psi), and an air filter change (regular paper - K&N lost mpg for me and didn't increase performance so I got rid of it). I have not changed the plugs, wires, or tranny fluid. I run premium gas and add a pint of octane boost/injector cleaner every couple of months. Could the problem be the plugs and wires, the tranny fluid, or is the engine just getting old? Or could it be the cats? Anything else I am missing??? I have never been able to figure this problem out. Please help.

 

The plugs should be replaced at 30,000 mile intervals. My bet is the plugs... especially with the hemi.

 

Try resetting the PCM. Mine has the annoying after 600 miles going to the eco-gas mileage mode. I can lay a set of 20' tire marks just from punching it at a stop light after I reset it. 600 miles later it is more like 2-5'.

 

Sounds unusual to me, mine is a 5.9 Magnum with about 76k on it and it still screams... matter a fact its been known to kill the little 6 cyl cars even with my oversized tires. Could it be because you unplugged your TCM (never really heard of doing this so sorry if the question sounds stupid)

 

Plug the TCM back in start the motor, idle up for 2 minutes, turn it off. Disconnect battery for 2 hours or more with headlights on, connect battery, turn on motor, idle up for 2 minutes, idle may drop on its own, & if it does computer resets. If you still have that problem could be that the cat converter could be plugged up. If you like burning rubber I suggest performance headers & cat converter. 10W-40 oil, & see if you could flush the torque converter, not just change the tranns fluid.

 

Reorg, how do you like your AIR RAM intake? i felt a nice little difference after i dropped mine in. whats that power harness your talkin about though?

 

I have the same problem. My ram feels lazy now

 

Ok, I may sound stupid on this one but Im at least, honest......Question, what is the TCM and where is it located on my hemi?? also what does it do, and is it best to just leave it alone or have it reset, and if reset is the answer, can it be done by me, and how is it done.......
Like I say, im new at these comptr and motor stuff... last horse car I had was in the late 70's.... long time ago, and no major comptr stuff.......