Denali LQ4 bad cats...delete?
06-07-2011, 01:09 PM
#1
Teching In
Thread Starter
iTrader: (2)
Join Date: Jun 2009
Location: CT
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Denali LQ4 bad cats...delete? Hi everyone...quick question, I tried a search but couldnt really find any specifics if the LQ4 is unique or not.
Have a 2003 Denali, awd, 6.0, 165k miles and its throwing catalyst inefficiency codes. The cat inefficiency codes were current and there was a misfire code in DTC history so im assuming the cats are pretty much shot. They are original, I guess its somewhat common for them to plug up around 150k or so.
New cats are anywhere between 500 bucks for aftermarket ones to 800 bucks for OEM ones from GM. I have no idea what the quality is on the aftermarket "direct fit" cats...Advance Auto and Rock Auto has Walker, Bosal, and Eastern Tech?
Heres what im thinking though, which would be a lot cheaper...I have EFILive, couldnt I just gut the stock cats (it has stock exhaust too) and disable the catalyst efficiency tests and diagnostics with EFILive? CT emissions does not do a sniffer test, all they do is a visual inspection and make sure there is no check engine light on....
Thoughts???
thanks
Ben
Have a 2003 Denali, awd, 6.0, 165k miles and its throwing catalyst inefficiency codes. The cat inefficiency codes were current and there was a misfire code in DTC history so im assuming the cats are pretty much shot. They are original, I guess its somewhat common for them to plug up around 150k or so.
New cats are anywhere between 500 bucks for aftermarket ones to 800 bucks for OEM ones from GM. I have no idea what the quality is on the aftermarket "direct fit" cats...Advance Auto and Rock Auto has Walker, Bosal, and Eastern Tech?
Heres what im thinking though, which would be a lot cheaper...I have EFILive, couldnt I just gut the stock cats (it has stock exhaust too) and disable the catalyst efficiency tests and diagnostics with EFILive? CT emissions does not do a sniffer test, all they do is a visual inspection and make sure there is no check engine light on....
Thoughts???
thanks
Ben
06-07-2011, 02:10 PM
#2
The element in one of my cats. came loose in my Z71 and was rattling like crazy. I decided to get some LLP shorties and a Magnaflow catted midpipe (direct bolt on to stock manifolds). Only reason I bought headers was b/c one of the bolts broke on my drivers side manifold. I payed 395 for the midpipe and it included 2 high flow cats.
Only part that sucks about the installs is that you have to remove the Transmission support, which isn't hard, It's just annoying.
Only part that sucks about the installs is that you have to remove the Transmission support, which isn't hard, It's just annoying.
06-07-2011, 02:16 PM
#3
Teching In
Thread Starter
iTrader: (2)
Join Date: Jun 2009
Location: CT
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
395 for both new cats and it was completely bolt on??? It worked with stock exhaust? I assume your Z71 was a 5.3...wonder if the 6.0 is different?
install isnt a big deal. Im just wondering if there is any "downside" or negative to simply gutting the plugged cats and retuning the ECM to ignore the rear O2's.
install isnt a big deal. Im just wondering if there is any "downside" or negative to simply gutting the plugged cats and retuning the ECM to ignore the rear O2's.
06-08-2011, 09:03 AM
#5
New cats are anywhere between 500 bucks for aftermarket ones
A good 2.5" aftermarket cat from Magnaflow is $125-$150 max. You can also get some cheaper thunderbolts for under $100 each or even a no-name for under $50.
I've been running some $38 cats for about 3 years now with no problems whatsoever and they work great at eliminating the smell.
There's no reason to spend more than $150 on a cat, $500 is insane.
