I have a 94 5.9L auto. And when I start it up cold in the morning. There's a horrible rattle in the exhaust. Once warm it disappears. I checked and I can't see anything loose. Almost sounds like it's inside the cat convertor. All the heat shields on the cat are tight. Could it be coming apart inside? And does this mean it needs replaced or will it be fine?

 

If it sounds like it's inside the converter, then thats where it's coming from. Yes, It's coming apart. Yes, it needs to be replaced and no it won't be fine for long if a big chunk breaks loose and clogs the converter.

 

Try banging on the converter. You might be able to hear the broken pieces inside.

 

i have a similar issue, its definitely a metal rattle but it dissappears when its warmed and usually only does when im starting to accelerate. odd thing is i replaced my cat a year ago, but i didnt fix my plenum till a few month ago. i sure hope i didnt plug up the new one sigh

 

The early rams came from the factory with bad cats. There was a recall on them. Here is what i found when i cut mine apart.

 

Wow I've never seen that. We'll I guess a new cat is a order. High flow or OE?

 

High flow.

 

I replaced mine with a magnaflow and two new NTK 02's, All good so far.

 

It's definitely in the cat. I hit it with a hammer and u can hear it loose in there. now I've found a direct fit high flow cat.(magnaflow) My truck only has 1 cat. But I'm thinking while I'm under there cutting and welding I might as well run a decent full system. The direct fit bolt to The manifolds so I won't be changing them. YET.... but I can't find any decent sounds I like online. If I put something on and I don't like the sound I have to take it back off. I personally like the stock sound but I'd like the performance gain from a good system. Is it gonna be a big changed running a cat back system in performance or will just changing to high flow cat be enough

 

On your truck, the biggest restriction in the exhaust is where the two pipes go into the cat. The magnaflow will fix that. Mufflers don't make any difference. (even no muffler doesn't make a difference.) Lots of sound clips on YouTube, find one that's close to what you are looking for, and run with it.