OK here is the current situation, and im going crazy. I have a 1998 Ram 3.8 6 cyl. the check engine light was on and pulled a bad O2 code, the truck has 120,000. I ignored it for a bit however ONLY WHEN WARM the truck is starting to loose power mostky up hills and at stops, and will sometimes backfire when I loose power. I put it in Neutral and rev it up, let the RPM;s come back down then put it in drive it goes back to normal. Truck has always been a dog, so I figured converter was plugged... I took it off and half the guts were missing from the inside of the cat... I just cleaned it out a little and put it back and the truck is still having the same problem... I just figured it was the cat, but obviously not... could this be a plugged muffler, or any other suggestions? Im lost here....

 

did u run it while u had the cat off??

 

Are there loose converter parts still it the converter?

 

a gutted cat wont cause any problems, i'd take it in and have them check your fuel pressure.

 

Im only pulling codes P0132, P0135,p0138... and it only acts up when its warm... The mechanic at my local shop told me that these trucks NEED a catalyc converter to function. Its telling my car how much fuel to send to the motor, and since both O2's are fire hot from the backfire they are just dumping more fuel into the motor... Its really bothering me, any more suggestions on this? Thanks

 

take your second o2 sencer out and zip tie it some where were it well get fresh air plug the hole with something see how it acts then

 

its possible your cat guts may have blown into the muffler and plugged it up.
you do need the front o2 sensor for it to run right.
you don't need a cat nor rear o2 sensor for it to run right, but without them, you might have a CEL

townly had the right question - did it run ok with the cat off ?

i'd remove the cat and see if it runs right with no cat and no muffler. if so, then finish gutting cat. if some of it broke out, more might follow. remove and clean out muffler and put it back together.

 

more than likely what happened as stated above is that some of the chunks from the cat clogged the muffler...

 

The 3.9 has the same plenum gasket issue. That's why the cat went bad. And I agree, the pieces are in the muffler.

 

Zman is right. I've seen a dakota have lots of problems because of a pretty nasty manifold leak. It is just a mini kegger after all.