Cat's, O2 issue

barspen

Active Member
Established Member
Joined
Jul 11, 2013
Messages
597
Location
Arizona
Hi All

Went for a short mountain drive last weekend and threw a coil pack/ignition CEL. Then I noticed i was getting about 50-miles per 1/4 tank (much less than normal). Also had a rattle that I thought was a loose side pipe bolt. Finally, started pulling coil packs to replace them this weekend and noticed a faint, but distinct sulphur smell near the driver side.
Originally thought it was the O2 sensors (I have new ones on order), but now i'm thinking it may be the cats. They are still the originals (9.5 year, 93K miles).
I plan to put a borescope down the O2 bung. I'm assuming any cat damage will be noticeable once i get a camera on it??
If I need to replace, does anyone know if the '13-'14 cats are a direct fit? I need to trim the end by the H-pipe to fit in my FRPP side pipe kit, but wanted to make sure the cat size and exhaust diameter was the same. THX in advance!
 

biminiLX

never stock
Established Member
Premium Member
Joined
Jan 17, 2003
Messages
13,253
Location
Toledo, OH
Forget about the factory cars, ok to use high performance aftermarket like Kooks.
I prefer free flowing exhaust.
Good luck.
-J
 

barspen

Active Member
Established Member
Joined
Jul 11, 2013
Messages
597
Location
Arizona
Forget about the factory cars, ok to use high performance aftermarket like Kooks.
I prefer free flowing exhaust.
Good luck.
-J

Not interested in headers. Considered OR pipe, but since I track at places with 96db limit and commute to work (not wanting to smell like gas), couldn't really go that route. From doing some research, very few options on catted mid with stock manifolds...and those who went down this path gave the aftermarket options pretty low marks.
 

barspen

Active Member
Established Member
Joined
Jul 11, 2013
Messages
597
Location
Arizona
Aren't the 13/14 cars 2.75 inch? The 07-09's are 2.5 inch.

I have a 2011.

Also, pulled the cats today and did a visual inspection and the look pretty good. No melted gunk, honeycomb looks in tact, just some light debris. Debating cleaning them and just replacing the four O2 sensors and calling it good.
 

biminiLX

never stock
Established Member
Premium Member
Joined
Jan 17, 2003
Messages
13,253
Location
Toledo, OH
A modified 95k mile car with factory cats?
Ticking time bomb to me.
Aftermarket catted mid pipe or weld in high performance cats into your stock pipes if you don’t want to go free-flowing.
Good luck.
-J
 

barspen

Active Member
Established Member
Joined
Jul 11, 2013
Messages
597
Location
Arizona
A modified 95k mile car with factory cats?
Ticking time bomb to me.
Aftermarket catted mid pipe or weld in high performance cats into your stock pipes if you don’t want to go free-flowing.
Good luck.
-J
Any recommendations on brands? Most of my forum (SVTP and others) research pointed to using factory cats if you don't go down the long-tube route. Sounds like a lot of bad experiences with 'hi-flow' and other aftermarket cat options.
 

SCGallo2

Balanced performance
Established Member
Premium Member
Joined
Mar 4, 2014
Messages
1,185
Location
Southern MD
My street car is at 700RWHP +/- and I still have stock manifolds, cats, and mid-pipe installed at 50k miles. Mid-pipe is off right now in the middle of a clutch replacement, and the cats look great. I monitor everything that goes on with my car, and I feel that I would detect a pending failure before it causes catastrophic damage... at least that's my hope, but I am not racing the car competitively. If I had to replace the cats, I would probably stick with OEM replacements, adapt 2013/14 GT500 OEM cats to fit my mid-pipe, or install GESi cats such as Kooks Green cats.
 

biminiLX

never stock
Established Member
Premium Member
Joined
Jan 17, 2003
Messages
13,253
Location
Toledo, OH
Stock cats from a 2020 GT500 or Hellcat are probably the best OEM, with ‘13-14 easiest to adapt. Kooks green cats or Stainless Works would be my starting point.
-J
 

Users who are viewing this thread



Top