I have a 98 Ram 1500. I was driving today and early on I could hear some kind of faint rattle on acceleration. I did not think much of it and thought maybe my exhaust was on its last leg since it is due to be replaced soon.

Later on today I was driving and the rattle seemed to have gotten a bit louder. After I turned off a highway road going about 60 I accelerated again and it bogged down big time. If I try to hit passing gear the rpms would climb, but the truck would not accelerate. It seemed like it was congested.

So I pulled off the road and while talking to a friend I attempted to go again. This time it accelerated a bit better, but not great. As I went and things heated up again the acceleration fell off. After about 10-15 miles I could barley accelerate up to 30 miles an hour. As it cools the acceleration gets a bit better, but is way off.

Also the rattle is a lot louder on acceleration. I have read some other threads and they say it sounds like marbles in a tin can and mention maybe a catalytic converter. Do you think that could be the situation? We have looked underneath and could not find anything loose.

It did throw a code and cause the check engine light to come on, but I have no idea how to get the codes. Is there any way of getting them manually without taking it in? I live in a smaller town and would have to drive 20+ to get to any autoparts that would pull the codes. I tried the key method and did not seem to work for me.

Any help here would be greatly appreciated. I don't want to take it into the shop just yet until I get some idea what it could be. Just to pull the codes they charge like $100.00.

 

1. Crawl under your truck
2. Next to the tranny, tap on the catalytic converter (cat)
3. If it rattles (like peanut brittle loose) then you have a clogged cat

Mine did the same thing. It would idle ok, but under load it would not even go 30mph, then it dropped to 5 mph in a matter of 10 min. It left me stranded.

4. If it is the cat, you can either remove/replace the cat or gut the cat (open it up, remove the insides and close it again)

good luck

 

+1 on the Cat... Replaced mine a couple months ago... Poor acceleration and cat rattled when hit with a hammer..

 

Thanks for the responses. I will check with a hammer shortly and will report back.

 

Bad cat = blown plenum!

 

I just went out and hit it in various areas of the cat and it sounds pretty solid.

 

tell me about it! replacing them both this weekend...

 

The catalyst material can be lodged in there tight, not allowing it to rattle, but it could still be plugged up. Can you redline the tachometer? You could try removing the upstream o2 sensor and take a quick run up the road to see if your acceleration is back, that'll tell you if its plugged.

 

If the cat is not rattling, then the noise you are hearing may be pinging. And pinging = bad plenum ,o2 sensor and cat(which does not have to rattle to be bad)! Use the search feature above for plenum gasket, and you'll find out all about it.

 

You can check the codes yourself by turning the key on and off three times, ending in the on position. The codes will show where the mileage usually is. It'll read something like "P0304." You might have more than one.
^For you '98 and abovers, this is right, right?

Then, once you have the code(s), search what they mean on here, then post what you have.