BBK Long tubes/stock catted h-pipe
08-10-2014, 07:14 AM
#1
1st Gear Member
Thread Starter
Join Date: Sep 2012
Location: New York
Posts: 51
BBK Long tubes/stock catted h-pipe
A little over a month ago I had BBK long tube headers and catted x-pipe installed on my 2010 GT. Car runs great, very happy with the setup. However after doing some research (after the fact), I have found that with my BAMA street tune and the 02 sensors functioning, I get the old p0420 and p0430 codes (catalyst efficiency below threshold). Ok, so my bad for not doing more research beforehand, but it would appear that hi-flow catts don't do a good enough job of scrubbing the exhaust gases to be fully compliant with EPA regulations. Seeing as I kept the old h-pipe and catts, can I have the stock h-pipe installed with the stock catts to the headers? How difficult is it? And would this bring the car back into compliance? I spoke with the folks at BAMA and they said that it may take a couple of tune updates, but they may be able to work it out, but I just want to know if this is an option if they can't tune the car enough to get the catts to work well enough.
08-10-2014, 07:45 AM
#2
6th Gear Member
Join Date: Jul 2008
Location: Acworth, GA
Posts: 12,260
Negative. Those stock cats as you probably know at a downward angle from the stock manifolds and are not directly under the car. Your BBK full length long tubes are already bringing the exhaust all the way down to under the car. I am sure someone can hack something up and make it work but I wouldn't.
08-11-2014, 09:50 AM
#3
A little over a month ago I had BBK long tube headers and catted x-pipe installed on my 2010 GT. Car runs great, very happy with the setup. However after doing some research (after the fact), I have found that with my BAMA street tune and the 02 sensors functioning, I get the old p0420 and p0430 codes (catalyst efficiency below threshold). Ok, so my bad for not doing more research beforehand, but it would appear that hi-flow catts don't do a good enough job of scrubbing the exhaust gases to be fully compliant with EPA regulations. Seeing as I kept the old h-pipe and catts, can I have the stock h-pipe installed with the stock catts to the headers? How difficult is it? And would this bring the car back into compliance? I spoke with the folks at BAMA and they said that it may take a couple of tune updates, but they may be able to work it out, but I just want to know if this is an option if they can't tune the car enough to get the catts to work well enough.
Good questions here. While I haven't heard of this being done I'm sure it's definitely possible with the right shop! Keep us in the loop on this!
Alex
08-11-2014, 12:31 PM
#4
5th Gear Member
Join Date: Dec 2006
Location: Redding, CA
Posts: 4,552
I had a muffler shop cut out my stock cats and put them in an aftermarket midpipe. They did a great job and the pieces bolted in and out with ease.
If you want to do that, just look round for a clean shop and be specific with what you want.
I think your easiest route is working with Bama.
If you want to do that, just look round for a clean shop and be specific with what you want.
I think your easiest route is working with Bama.
08-11-2014, 04:07 PM
#5
1st Gear Member
Thread Starter
Join Date: Sep 2012
Location: New York
Posts: 51
I will update as time goes on. I did speak with the folks at BAMA, and was told it may take a couple of tries, but high flow catts for the most part just don't have enough "catalyst" material to adequately scrub the exhaust gases. I should've done more research before making the purchase. I guess if the fuel air mixture could be leaned out a bit, maybe that would make enough of a difference. Only problem is, if you lean it too much, you can melt the catts, along with the usual problems of a lean mixute. I received an updated street tune this morning, and I will try it out when I'm back from vacation.
08-12-2014, 09:07 AM
#6
I will update as time goes on. I did speak with the folks at BAMA, and was told it may take a couple of tries, but high flow catts for the most part just don't have enough "catalyst" material to adequately scrub the exhaust gases. I should've done more research before making the purchase. I guess if the fuel air mixture could be leaned out a bit, maybe that would make enough of a difference. Only problem is, if you lean it too much, you can melt the catts, along with the usual problems of a lean mixute. I received an updated street tune this morning, and I will try it out when I'm back from vacation.
Alex
08-14-2014, 09:16 AM
#7
I have the same setup from BBK. And from reading your info, we both live in New York. I just went for my first inspection with my high flow catted x, I've had it for a year now.
I had some trouble recently because P0430 (bank 2 below efficiency) kept coming up when every time I did a drive cycle to get rid of the p1000 that i got after clearing the p0430. I went underneath, swapped the 02 sensors from bank to bank and closed a 1/2" gap where the midpipe meets the overaxles. After that, it passed.
You should be able to pass too since we have the same setup. Make sure you run the car on the street tune, mine is 91, and if your cat code(s) keep popping up, check your pipe connections for gaps.
I had some trouble recently because P0430 (bank 2 below efficiency) kept coming up when every time I did a drive cycle to get rid of the p1000 that i got after clearing the p0430. I went underneath, swapped the 02 sensors from bank to bank and closed a 1/2" gap where the midpipe meets the overaxles. After that, it passed.
You should be able to pass too since we have the same setup. Make sure you run the car on the street tune, mine is 91, and if your cat code(s) keep popping up, check your pipe connections for gaps.
08-14-2014, 12:11 PM
#8
3rd Gear Member
Join Date: Sep 2011
Location: DE
Posts: 546
Another option instead of having the factory cats welded in, just add 2 more high flow cats to the BBK pipe. That way you can get the right inlet/outlet size to match it up to the pipe. This may be easier than getting the stock cats to fit the pipe. Only thing would be how much it affects the sound of the car.
08-15-2014, 07:49 AM
#9
1st Gear Member
Thread Starter
Join Date: Sep 2012
Location: New York
Posts: 51
Thanks for the responses. I've been hoping that someone with the same setup would chime in. I was wondering if I was the only one with this particular problem, and if not, what has been done to correct the problem. After all, what's the sense in keeping the cats if they don't do the job they're designed to do? I had the shop that installed the setup check for exhaust leaks, and tighten up the headers last week. I know from past experience that headers, after a few heat cycles can loosen. I want to keep the car EPA legal, except when/if tracking it.
As for installing a second set of hi-flow cats, that makes a certain degree of sense, giving more catalyst surface area to flow the exhaust, but what about the post cat 02 sensors? Not sure they could be re-located without some serious modifications...but will look into that if nothing else works. I'm just back from vacation, and I'm going to load up the updated BAMA street tune over the weekend and see how it goes. I'll update when that's done. Thanks again for the input!
As for installing a second set of hi-flow cats, that makes a certain degree of sense, giving more catalyst surface area to flow the exhaust, but what about the post cat 02 sensors? Not sure they could be re-located without some serious modifications...but will look into that if nothing else works. I'm just back from vacation, and I'm going to load up the updated BAMA street tune over the weekend and see how it goes. I'll update when that's done. Thanks again for the input!
