Gutting the Magnaflow highflow cat
06-15-2010, 01:56 AM
#1
Senior Member
Thread Starter
Gutting the Magnaflow highflow cat
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.
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.
06-15-2010, 07:36 PM
#8
Senior Member
Thread Starter
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.
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.
06-15-2010, 10:38 PM
#12
Senior Member
Join Date: 06-26-09
Location: Rochester, MN
Posts: 609
Likes: 0
Received 0 Likes
on
0 Posts
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?
06-16-2010, 03:14 PM
#14
Senior Member
Thread Starter
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.
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.
06-27-2010, 11:53 PM
#17
New Member
Join Date: 06-27-10
Location: Las Vegas
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
I recently gutted my magnaflow 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.
Last edited by gordonjj; 07-06-2010 at 01:14 AM.
06-28-2010, 12:00 AM
#18
Banned
iTrader: (2)
Join Date: 06-03-10
Location: HBG/Hanover
Posts: 6,919
Likes: 0
Received 0 Likes
on
0 Posts
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?).
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?).
07-01-2010, 01:31 AM
#19
Senior Member
Thread Starter
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.
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.
Thread
Thread Starter
Forum
Replies
Last Post