Exhaust option for smell

[Carlos Mendoza]

Hello Everyone, I’m in need of your expertise. Has anyone heard of running high flow cats after an x pipe application just for the sole purpose of toning down exhaust fumes? My 02 Tahoe has speed engineering LTs and speed engineering dual x pipe. Love the sound, but the smell is just becoming too much for the wife and kids . Reason why I’m asking about after an x pipe and not before, is because there’s not much room on the driver’s side before it crosses below the transmission.

 

[Scottydoggs]

cats should be close to the header collectors. im sure a good shop could fit them in there.

 

[ivin74]

Hello Everyone, I’m in need of your expertise. Has anyone heard of running high flow cats after an x pipe application just for the sole purpose of toning down exhaust fumes? My 02 Tahoe has speed engineering LTs and speed engineering dual x pipe. Love the sound, but the smell is just becoming too much for the wife and kids . Reason why I’m asking about after an x pipe and not before, is because there’s not much room on the driver’s side before it crosses below the transmission.

That's why it's not recomended to dump the exhaust before the rear axle on these SUV's. I had high flow cats after the long tube headers on my 03 Silverado SS, the cat on the drivers side was below the transmission

 

[Carlos Mendoza]

Thanks for your input guys, really appreciate it!!!!! I ordered some flowmaster cats and hoping I can fit them in. That’s what I get for trying to take the easy way out and ordering the speed engineering dual x pipe to minimize the amount of welds I had to do .

 

[Carlos Mendoza]

Thanks for your input guys, really appreciate it!!!!! I saw that there’s exhaust kits for corvettes that have the cats after an x pipe

 

[Tonyrodz]

Thanks for your input guys, really appreciate it!!!!! I ordered some flowmaster cats and hoping I can fit them in. That’s what I get for trying to take the easy way out and ordering the speed engineering dual x pipe to minimize the amount of welds I had to do .

Do you have a pic of your underside? I also have the speed engineering long tubes on my 03, with their y pipe dumping into the factory single exhaust--no cats. Loud AF!

 

[iamdub]

Thanks for your input guys, really appreciate it!!!!! I saw that there’s exhaust kits for corvettes that have the cats after an x pipe

Cats really should be as close to the collectors as possible. If they're too far downstream, the exhaust gases won't be hot enough to propagate thorough catalytic reaction and burning off of the hydrocarbons, leading to carbon build-up that will clog the cats.

I'm kinda in the same boat as you. I have some Magnaflow cats that might would fit in the Y-pipe. I'm not chopping up my headers, but I'll slice and dice on the Y-pipe as needed. Already had to to install it.

 

[Xsbank]

One truck with no cats is like 200 lawn mowers. Do your part! Porsche gets 500 hp from a normally aspirated engine 1/2 the size of a Yukon, they use cats.

 

[kses123]

He literally posted that he ordered flowmaster cats.

 

[Carlos Mendoza]

Do you have a pic of your underside? I also have the speed engineering long tubes on my 03, with their y pipe dumping into the factory single exhaust--no cats. Loud AF!

Not at the moment. Kinda wish I would have just went with the y pipe, the x pipe set up gets really close to the tranny, when it jumps back up over the other side. I bet it’s loud AF lol. I had 2 3” flow fx after the x pipe, really loved the sound at idle, but driving around was too much. I went with DI/DO 3” Maggie to tone it down. It technically has a double x pipe now, I know kinda stupid lol, but don’t know many ppl that had done it.

 

[Carlos Mendoza]

Cats really should be as close to the collectors as possible. If they're too far downstream, the exhaust gases won't be hot enough to propagate thorough catalytic reaction and burning off of the hydrocarbons, leading to carbon build-up that will clog the cats.

I'm kinda in the same boat as you. I have some Magnaflow cats that might would fit in the Y-pipe. I'm not chopping up my headers, but I'll slice and dice on the Y-pipe as needed. Already had to to install it.

View attachment 356923

Thank you for that info, it’s what I needed to know. I will do my best to fit them in after the collectors.

 

[Carlos Mendoza]

One truck with no cats is like 200 lawn mowers. Do your part! Porsche gets 500 hp from a normally aspirated engine 1/2 the size of a Yukon, they use cats.

Ummmmm ok. Lol

 

[Carlos Mendoza]

Like I said before, I really appreciate everyone’s input and help!!!!!! Long time lurker and this forum has helped me worked on my 07 esky and 02 Tahoe.

 

[Tonyrodz]

Here's an older cold start video.

And a little smoke.

 

[Tonyrodz]

Not at the moment. Kinda wish I would have just went with the y pipe, the x pipe set up gets really close to the tranny, when it jumps back up over the other side. I bet it’s loud AF lol. I had 2 3” flow fx after the x pipe, really loved the sound at idle, but driving around was too much. I went with DI/DO 3” Maggie to tone it down. It technically has a double x pipe now, I know kinda stupid lol, but don’t know many ppl that had done it.

My y pipe also is close to my trans.

 

[Carlos Mendoza]

My y pipe also is close to my trans.

Maybe it’s speed engineering intermediate piping??? Cause the x pipe gets close like your y pipe

 

[Carlos Mendoza]

Little update, got them in. Just waiting to weld them up tomorrow and see what happens. Hopefully it doesn’t tone it down too much. I like the way it idles without them.

 

[iamdub]

Little update, got them in. Just waiting to weld them up tomorrow and see what happens. Hopefully it doesn’t tone it down too much. I like the way it idles without them.

Is that crossover pipe sagging cuz of the slack in the slip couplings? It looks to be hanging dangerously low.

 

[Tonyrodz]

Maybe it’s speed engineering intermediate piping??? Cause the x pipe gets close like your y pipe

Probably. Long tubes with the y--all Speed Engineering pieces--were supposed to be compatible with my 4wd--a direct bolt on and go. It wasn't. Only thing I was happy about was the price of the headers.

 

[Carlos Mendoza]

Is that crossover pipe sagging cuz of the slack in the slip couplings? It looks to be hanging dangerously low.

Yes, but it goes up and down quite a bit. I left it like that for the night, it got too dark and cold, not going to lie I bitched out. Lol