I have an 04 with a little over 246k on it and had zero engine issues until the other day. I was driving and all off a sudden the engine was hesitating and had very little power. The exhaust smelled really rich and the engine seemed to be missing. I have changed the ECM, the plugs and wires and the injectors. It's still idling rough and smells rich. If I get the RPMs up to anything above 1,500, the engine seems to run smoothly. I'm stumped and don't know where to go from here. I need it for work. Thanks in advance.

 

Start with a fuel pressure and leak down test. Also look inside your throttle body at the plenum and see if you have any washed out spots to indicate a fuel leak.

 

Try unplugging the EGR and see if the power increases.. I just had that happen to my 2000 on the way to work . Would fall on its face from a take off but as soon as I unhooked EGR it takes off like a jet. Will pull and clean or replace tomorrow.

 

2001 was the last year they used Egr valves on the 4.3l