I just bought an 03 super cab 4x4 from my friend who was the original owner, it has 276,000 miles on it and it runs good but it just doesn't seem loud enough for the type of exhaust it has. It's got true duals with an h pipe , no secondary cats, and no mufflers. I ran the same setup on an 01 SC I used to have and it was definitely louder with a lot of crackle, could the primary cats be bad enough to cause this but not really hurt the performance? Or is there another reason? Thanks.

 

If the remaining cats it has in it are clogging up, a decrease in sound is one sign. But the main sign would be sluggish performance, poor fuel economy, and possibly a bad egg type odor.

Another factor would be the exhaust tubing size. The thinner it all is, the raspier and calmer the tone may be. Larger pipes have more of a rumble and a deeper tone.

The H pipe crossover could be a poorly made piece and causing a sound reduction.

The size of the exhaust tips will effect the audible level also. Smaller and shorter they are, the less of a megaphone echo effect they will produce.