I believe my Magnaflow cat in my ZZP downpipe to be clogged. I have a hissing sound under acceleration that isn't a vacuum leak, a rather rough idle, and a wot box

Has anyone gutted this setup? I have the factory muffler and resonator in their OEM locations. I have the ZZP Midlength header and 2.5" stainless piping after the ZZP downpipe.

Thoughts on this? I know gutting the factory cat supposedly sounds like ass but that's probably largely due to the retarded coffee can design of the thing, and the crushed piping causing turbulence.

The car also seems to be sluggish below 3k or so as well.

If I look into the cat with a maglite, will I be able to tell if it's clogged?

Thanks in advance for your kind words.

 

any warranty from magnaflow or ZZP??

 

No, I bought the piece used a while ago.

 

quit crying and gut it

 

catless lsj's dont sound the best imo

 

Hold it up to light, can you see through it? Not clogged.

Can't see through it, or openings appear to be pinpricks? Clogged.

Are you overboosting?

 

I recently gutted my high flow cat and it makes the car sound a little bit raspier. If you have an aftermarket catback I would not recommend gutting it because it will sound like garbage unless you add resonators.

 

It's not boosting any higher than normal. I held the RPMs at 2500 and the vacuum sat at 20, so maybe it isn't clogged.

I'd rather not gut it because LSJ's apparently sound awful catless. I'd rather avoid that as I prefer the OEM sound and quietness that my car currently has.

 

does catless sound bad with gmpp

 

I couldn't tell you, as I've never heard one in person.

 

weel poo i just got my ottp catless today

 

Dont gut your cat if your not overboosting. The problem lies elsewhere. You might have a broken flex pipe section. That or you got a leak somewhere else. Notice any soot building up anywhere around your flanges or flex section?

 

it sounds fucken awsome

 

Yeah, it's not clogged.

I hit it with a rubber mallet and it sounded just like hitting a hollow pipe. It's black inside but it's definitely not clogged. Boost is ~13psi at 4500rpms with a 3" pulley.

 

really? got any vids

 

i figured ud see it on here but u need to delete some of ur inbox lol so i can message ya bak

 

Correct. It sounded so crappy on mine, too bad I had to do the resonators again. I feel not everything agrees to gutting

 

This is a clogged cat. Damn GM tune.



If you no see diz you no have clog cat. Lol.

Yes catless sounds like ass and if you're not overboosting your cats not clogged, at least not yet.
The hissing, if it happens under boost, is in the flex or a leak somewhere else (the header->dp flange?).

 

I gutted mine yesterday. I have a WOT box so that's probably why it clogged.

It sounds pretty much the same as before, just a little louder and a deeper tone. It also backfires a little bit more on decel.