soundmaster

My aftermarket high-flow cats are making a sorry-*** old-car noise whenever I accelerate. I just recently put on these cats - they are extremely lightweight and are not welded but bolted. What can I do to make it get a cleaner sound? Should I weld it? Is there possibly an air leak in the cat? Are there other cats I can use? the car sounds like air flowing out of the cat or something... kind of like a leak... do all the aftermarket cats sound like this?

greekss

are these new,.... if not they sound like they may be burn up ???? maybe ??? not sure

slik98z

if they are new, package up the one that is making the noise if its both ship em both back to where you got them from. On occasion a company that makes catalytic converters can screw up the placement of the screen inside. I had a set of magnaflow hi-flow cats on an x pipe for my old mustang, had an ackward sound to it, kind of a winding up sound. hard to explain. I took the cat off and ran a small weld at the very top of teh screen, that was where teh gap was and creating the sound. it didn't take the sound away 100% (im sure there were other little leaks else where i couldn't see) but it was good enough for government work. i can't tell you if it was ok for emissions cause i traded in the car 3 weeks later to get my z28 lol. good luck, if worse comes to worse i think you can pick up magnaflow hi-flow cats for 60 bucks a peice. (i have them on my camaro now and i had no problems this time.
God luck
Travis

soundmaster

alright, I'm going to take out these cats and get some new cats in about 2 weeks.

Dope

iTrader: (2)

Maybe you just have an exhaust leak? You didn't really describe the sound.

Dope

soundmaster

it sounds sort of like a quiet blowoff valve going off nonstop but its coming from the cats. or some kind of high-pitch hissing sound.

soundmaster

i mostly hear it when i have the windows down and especially when I pass cars or objects when pressing the gas. when the car was parked, i had someone press the gas while on neutral then i checked outside the car to see where the sound was coming from. it wasnt coming from the back, not under the hood near the headers, but underneath the car where the cats / ypipe is located

soundmaster

also, do any of you think that my problem is similar to the problem in this link:
https://ls1tech.com/forums/generation-iii-external-engine/137725-rasp-what-can-done.html
... the first 3 threads?

Dope

iTrader: (2)

You try feeling around under there for any air? An exhaust leak usually is a hissing, or sometimes ticking sound. It's especially noticable when parked next to a wall or another car. After a few days, you should be able to see the leak too, there will be black carbon residue on the pipes near the leak.

Dope

DaddySS

Put the car up on ramps, start it up and go under there and check it out. If you don't see the problem right away (you probably will) put on a pair of gloves so you don't burn yourself and feel around until you hit the spot where the noise is coming from.

soundmaster

since i'm no mechanic, i took it to a muffler shop and let these guys do what they do best in finding out if there's any problems. what they had found was that there were anywhere between 3 to 5 leaks. the guy put something in his ear which hooked up to some tube and started listening to find where the sound was coming from while the car was still running on the lift. they're going to use some kind of glue to patch up the leaks - at least this is what the problem might be as of now. it involved the areas near the cats and the ypipe.

slik98z

pretty easy fix, tell them glue nothing tack weld and spot weld them bitches.