" Tru Duals "

scootertrash2004 · June 8, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

2007VictoryRed · June 8, 2009

True Dual is its own pipe per banks of the engine,(left side own pipe, right side own pipe) they never come toghter unless you are going to have a X pipe, To be honest with you I dont think theres enough room to have true duels, But I never been under a 09 truck yet. I know thats what I wanted to do, and all the shops said no it cant be done. Also I would check to see if it will pass somg in your area, It will be the sh*ts if you have to Remove all the pipe for you to pass smog. And welcome to Gm Trucks, Also its going to be loud.

GPGuy · June 8, 2009

Welcome to the forum.

My best advice would be to find a shop that does custom exhaust work and they should be able to tell you if it can be done and if it will pass smog regulations in your area.

HTH ;)

crazy1mg · June 8, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

I just had my 09 silverado done on Friday, I had it done by a custom shop. There is enough room, dual magnaflows out to 3.5" tips. Sounds great.

scootertrash2004 · June 10, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

I just had my 09 silverado done on Friday, I had it done by a custom shop. There is enough room, dual magnaflows out to 3.5" tips. Sounds great.

ok did your exhaust guy say you had 3 cats? I went to the GMC dealer and they looked up the exhaust on my truck and I do have 3 cats. One right off each exhaust manifold, then it Y's into a single pipe goes into a 3rd cat then into muffler

Bostonsfavson · June 10, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

I just had my 09 silverado done on Friday, I had it done by a custom shop. There is enough room, dual magnaflows out to 3.5" tips. Sounds great.

ok did your exhaust guy say you had 3 cats? I went to the GMC dealer and they looked up the exhaust on my truck and I do have 3 cats. One right off each exhaust manifold, then it Y's into a single pipe goes into a 3rd cat then into muffler

That's probably not a catalytic converter you're seeing, but rather the resonator.

scootertrash2004 · June 10, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

I just had my 09 silverado done on Friday, I had it done by a custom shop. There is enough room, dual magnaflows out to 3.5" tips. Sounds great.

ok did your exhaust guy say you had 3 cats? I went to the GMC dealer and they looked up the exhaust on my truck and I do have 3 cats. One right off each exhaust manifold, then it Y's into a single pipe goes into a 3rd cat then into muffler

That's probably not a catalytic converter you're seeing, but rather the resonator.

No the parts list called it a cat also and the service manager said they put 3 cats on them in 09

Darkanion · June 10, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

I just had my 09 silverado done on Friday, I had it done by a custom shop. There is enough room, dual magnaflows out to 3.5" tips. Sounds great.

ok did your exhaust guy say you had 3 cats? I went to the GMC dealer and they looked up the exhaust on my truck and I do have 3 cats. One right off each exhaust manifold, then it Y's into a single pipe goes into a 3rd cat then into muffler

I'm not doubting what you're saying, but.. Could you take a picture of that third cat? I remember my stock exhaust having something right after the two pipes came together. But, it wasn't a cat.. It seems odd to me that 2 yrs later, they'd decide / figure out that these trucks need another cat.

longhorn_giant · June 10, 2009

One thing to consider when deciding on an exhaust is back pressure. The engines are designed to perform better with a certain amount of back pressure, and you'll loose a lot of that with true duals I think. If I remember correctly, the lost performance is more on the low end, but I might be COMPLETELY off.

Stevens03 · June 10, 2009

Def. low end can be lost. I ran flowmaster on my 5.3 and lost alot of low end torque. Switched to Magnaflow and gained it back.

crazy1mg · June 10, 2009

I've got a 2009 Sierra w/5.3L Does anyone know if I can remove the 3rd cat, and install tru-duals?

I just had my 09 silverado done on Friday, I had it done by a custom shop. There is enough room, dual magnaflows out to 3.5" tips. Sounds great.

ok did your exhaust guy say you had 3 cats? I went to the GMC dealer and they looked up the exhaust on my truck and I do have 3 cats. One right off each exhaust manifold, then it Y's into a single pipe goes into a 3rd cat then into muffler

He said its a resonator not a cat, but I can tell you there were not o2 sensors there or any other type. I did notice a little low end gone with my magnaflows, I am going back this week to have him install an H-pipe. It wasnt a huge difference but my main concern is to level out the flow and tone, there is a slight offset resonation without the H-pipe at low speeds that sounds like a helicopter in the cab.

hgl800 · June 10, 2009

If they tell you "it can be done cause there isn't enough room" There full of chit. That just means they don't have one of there exhaust system for dummies that are all pre built kits. Any shop that will do custom exhausts will do it, unless they are just lazy. I wouldn't be to concerned with the "3rd cat" or resinator or whatever it is, just cut it off. And yes with true duals you are going to lose a bit of bottom end, that snappy feel because of the reduced back pressure.