Loss of power, intake poping, oh my
 

'96 4.0 aw4 np231

Last weekend while out wheeling I got hung up on the muffler. Ended up coming loose and hanging from the o2 wires. Got that fixed and on the way home it threw a CEL for the rear o2. Figured one of the wires ripped out. Replaced the o2 and got the exhaust welded back up and now I have popping coming from the intake and imtermintent loss of power.

Loss of power only happens at part throttle. At WOT it runs fine. When cruising off throttle it feels like it wants to stall but never will. If I take it out of gear it will idle and rev up with no issue.

Fuel pressure while running is 49psi. Plugs are tan in color. No vacuum leaks. Both o2 sensors are new. Just put a new cat in as well. Checked the fuse's as well.

What am I missing? Any ideas? :001_huh:

Edit: Read some more. TPS and Up Stream o2 seem to be the common issue. Will have to check those tomorrow, its dark now.

CEL on?

It gave me P0138. Front o2, heated.

I have a brand new Bosch o2 in there and it still throws the CEL. From reading around the web, others had a similar lean mixture (throttle hesitation) after swapping to a Bosch o2. They recommended a MOPAR o2 only. So come morning Im going to unplug the upstream o2 and drive it around. If the lean issue stops then I will know its bad and will be replaced with a MOPAR unit.

Other culprit may be TPS. I will have to find procedure for testing it.

Since you pulled the wires out there's a chance that you shorted out the wires and blew the O2 fuse.

I checked all the fuse's in the Power Distribution Center. I pulled each one out, checked, cleaned and then put back in.

Do you happen to know which one exactly I should be looking at?

It's in the fuse block on the passengerside (footwell).

Probably why I couldnt find it in the PDC. haha

Thanks, I will check that as well.

Passenger side or drivers side? I didnt see a fuse panel on the passenger side.

Mine pops and loses power when cold and I've got a Cracked exhaust manifold. Yours okay?

Fixed it!!!

Loose wire for the o2 connection block side. Guess I pulled a little too hard on the connection when taking it a part. Thanks Frankz for the help, as always you are the man!