About 3 weeks ago, I bought a 2000 Dakota Sport 4x4 with the 3.9 V6 and a 5 speed. Since the day after I bought it, I've had a problem with the truck occasionally sputtering at low speeds. It only does it when first driving (within about a half mile or so), then doesn't do it again after that. Once I get going, it drives without a problem. I can hear a rattle from under the cab (sounds like it's under the passenger side), and I only hear the rattle when it sputters. It feels like it's going to stall, but doesn't. It almost seems like a catalytic converter, but it's too random for that. If I accelerate hard, I can usually avoid it happening, but with stop lights and such that's not always possible. I had the fuel injectors and throttle body cleaned when I had the truck inspected, but that didn't fix it. I also have the P0455 code, but that didn't come on until about a week after I first had this issue. I'm on an extremely limited budget, and need to limit the trial and error as much as possible. Any help would be greatly appreciated!

Thanks,

-Tom

 

Do you have any of the service records? Really the best way to pin point a problem would be to figure out what has already been done. You could pull a few of the plugs and check o see if they are fouling, check the plug wires for any burn spots to make sure they are not shorting out. From there I would call the local parts store to see if they can check the coil to make sure it is getting enough spark. The ratteling your hearing could just be a heat shield, as mine tend to rattle when it is under a load.

 

sounds like a bad cat to me. We have a chevy 1500 work truck that does the same thing. After it warms up it will act very similar to how you describe, especially under load. If you open the throttle wide it seems to go away, we are pretty sure it is a bad cat. That is where I would start if you aren't getting any engine codes. You could also look for a vacuum leak.

 

I've got the same problem. Took the truck into Goodyear for front pinion shaft seal replacement and thy said the cat is shot and is making that rattling sound. It's doing it when hot because with the heat the cat gets worse and in drive because there's more pressure. I just picked up a new precat 02 sensor and a magnaflow cat all from summit racing store last night for 150 bucks. Have both put on tonight at friends shop

 

I'll be honnest.. I have a puttering/shuttering issue from a stop or to a spot.. does not really feal like a CAT issue.. Mine does it hot or cold.. sometimes it does it sometimes it does not.. but most of the time it does.. so someone figure out what the issue is.. H AHA>.

 

You say you have a 3.9 V6, right?
Well, you may have a plenum issue. Search the 2nd gen Ram forums for the plenum. Basically, you are loosing vacuum and your truck is turning into a dog. Also will want to replace the cat if the plenum is at fault.

 

I think I am just going to remove the CAT.. and put a pipe in place.. and if/when i go for inspection ill put it back on.. just use some clamps like stock has now..