I'm driving a 2001 Dodge Ram 1500 5.9l 4x4 as my daily driver work truck. Has 223,000 miles and I've had it for about 5 years now. 75% of the time while driving, when I let off the gas to come to a stop, it seems to go to neutral for some reason and at times, will tend to idle extremely low when this happens and tries to die. When I do come to a complete stop, the idle jumps back up to normal. I've replaced transfer case fluid (ATF4), replaced plugs, wires, distributor rotor and cap, coil pack, belt, and fan clutch. The transfer case does have a small leak from the front output seal going to front drive shift. Also, don't know if this has any revalance to that problem, but once I get to bout 50mph in 5th gear, I don't have much power at all.

Any tips or suggestions would be greatly appreciated. I'm a YouTube and Google mechanic and resort to a lot of DYI due to budget restrictions. Thanks.

 

??? Auto or manual transmission?

 

Sorry, yes it's an automatic. Also, yes when it gets to 5th gear (or 4th, the highest gear), I lose nearly all power. It will still continue to climb in speed, but very marginally. Forgot to mention that I also changed air filter as well. Planning on checking and cleaning/replacing O2 sensors and checking the cat converter and cleaning the throttle body.

 

Forgot to mention that I had the transmission and torque converter looked at and was told that they don't need replacing. Although when I put it into reverse, it goes into gear pretty rough with a slight jersey and knock. Also at times when shifting from 2nd to 3rd gear, if I let up off the accelerator right before the shift, it transitions pretty rough with a jerk and some noise. Being told that the tyranny was fine came rather surprising.

 

If it hasn't had the intake plenum gasket changed, that would be where I would start. Look down through the throttle body and see if there is a puddle of oil on the bottom of the intake. If it's been leaking a long time the oil may have plugged the catalytic converter. This is also a good time to install a new timing chain. The plenum only needs a Felpro gasket and shorter bolts. The original bolts are to long and bottom out, causing the gasket to fail.

 

Think I would pressure test the catalytic converter as well.... Might be partially clogged.