SS_Black_Attack

There is a new Service Bulletin for SS models with the 5.3L V8. If your car feels like it is missing or slacking you get a new exhaust system FREE!

Now one may ask way would you care since most of you are replacing the stock exhaust for a cat-back system? Well the answer is clear to me now, that I have done some research. The stock exhaust offers a lot more torque out of the hole than a modified exhaust system. Why? Because our smallblock needs the backpressure. So... instead of running a Flowmaster, Dynaflow, magnaflow, borla, etc., one would be smart to run a stock exhaust with auto cut-outs right after the exhaust manifolds. Why? Now you capitalize on the higher lowend torque of the stock exhaust and the highend horsepower of the low or no back pressure exhaust systems. Come out of the hole stock, hit the auto cut-outs as your car approaches 4500RPM, your car goes from being a quiet kitten to a full raging lion and your tearing up the road. Race over... hit the switch and your car is a quiet kitten again.

MagnaPilot

Can you elaborate on the conditions of this TSB? My car idles like crap, and sometimes stumbles, I've wondered if something else is going on.

Is anything changed on the new exhaust?

06MonteSS

hey SS_Black, does that same info/theory apply if you left all the stock pipe, and replaced mufflers only???

all I did to mine was cut off the stock mufflers/tips, and put on new flowmaster mufflers/tips... all my pipe is still all stock...

Taz34SS

iTrader: (2)

Thats kinda funny, because I have been telling people about any LSX car needs back pressure. Anyways, I have checked the GM Service program and there is NO bulletin for our cars as of 10-30-07 per GM. IF you have a GM bulletin number, please post it as I can also look those up aswell.

The problem would be more in the Cat and not the exhaust. The exhaust is really very free flowing from stock. The res acts as a 3rd muffler. I am wondering * if this is true * if GM found the downpipe to not be the correct size or the cats are flowing too much.

I will not say much more untill I look into this Bulletin... If there even is one.

06MonteSS

cool, so leaving the all the stock pipe and just replacing the mufflers is better than replacing everything.... woohoo!!

Thanks for the info Taz... I'll be checking back to see what comes of this...

djfeezy

Does anyone have any proof that there is a low-end loss with an aftermarket system? I've had my custom 3" flowmaster system and my 3" hogan downpipe with high flow cat installed for some time now and do not feel as though I've lost any low-end. I do however feel the gains that this set up has givin me.

IMPALA SS 07

ive got a custom 3" pipe into a 2 1/2" y-pipe and flowmaster 40 series mufflers and my car has tremendous top end power compared to the stcok system

06MonteSS

right, TOP end... they're talking about LOW end power/torque... which I bet you lost...

Taz34SS

iTrader: (2)

Any car HP and TQ numbers are really based off of stock OEM exhaust. ONce you start to replace that with Bigger, more free flowing items, your low end is going to take a hit, while your top end is going to improve. Now, if you add a bigger downpipe with say Turbo/SC or even Rocker Arms, then it will make up for some of the loss, but not all.

Again, tomorrow I will check up this so called "TSB" and see what the REAL Story is. I cant image GM replacing a **** load of SS/GXP cars with there 304SS exhaust. This really doesnt make any sense to me at all.

Taz34SS

iTrader: (2)

Per GM Service Bulletin program/site, there is nothing posted for any C 2005-2008 W body cars with the 5.3 V8 reguarding the exhaust system. So I ask you, what is the bulletin number, as there is nothing listed from GM on this?

SILVER LS4

TaaDaa!!!!! Document ID# 1913553
2006 Chevrolet Impala


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Subject: Exhaust Moan Noise/Vibration Felt or Heard at Idle (Replace Muffler Assembly) #07-06-05-002 - (03/07/2007)



Models: 2006 Chevrolet Impala, Monte Carlo

with 3.9L Engine (VIN Code 1 -- RPO LZ9)




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Condition
Some customers may comment on an exhaust moan or vibration that can be felt or heard at idle when vehicle is in gear.

Correction
An updated muffler assembly is now available. The muffler assembly is a one-piece assembly which includes the exhaust pipe, mufflers, and tail pipes. This updated exhaust assembly has been tuned to eliminate the exhaust vibration. Follow the muffler replacement information for dual outlet in SI.

Parts Information
Part Number
Description

15916870 (Impala)
Muffler Assembly

15916871 (Monte Carlo)
Muffler Assembly


Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

L2905
Exhaust System (Complete) -- Dual -- Replace
Use Published Labor Operation Time




GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© Copyright General Motors Corporation. All Rights Reserved.


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Document ID# 1913553
2006 Chevrolet Impala

SILVER LS4

Now, do you really need all that low end torque on your already tire frying front driver????. When I traded my Impala in, I put it all back to stock (except for tune), and not on the same day. On the day I installed the stock down pipe, I did notice a little more off idle grunt, it was EASIER to chirp the tires. Unfortunately in this case that doesn't mean you have a quicker car.

SILVER LS4

Oh, and by the way, that above bulletin is for 3.9 v6 cars.

Taz34SS

iTrader: (2)

Not to sound like an ******* here, but you first post this is for the 5.3 LS4, on a LS4 fourm, then you bring up a bulletin about the 3.9 after I point out there is no service Bulletin for the c 2005-2008 w cars? WOW. I would really hate to buy a car from you if you cant get info correct. It took me all of 30 seconds to do a search on year, make and model along with Service Tech Bulletins related to car or part.

BuffaloSS

iTrader: (3)

Taz...you only sound like 1/2 an ******* ...b/c while it WAS he that brought it up in the first place, it was SILVER LS4 that corrected him with the 3.9 bulletin

SILVER LS4

Easy ya hater. At least I was able to address the issue with a better answer than just a "no there isn't". I don't sell cars either, and I would hope you don't either. I didn't post any incorect info either, Einstein. AND, it only took me 29 sec to do a search.

Taz34SS

iTrader: (2)

Well, I corrected him because I looked in the CORRECT place with the LS4 W body cars.

Anyways, thanks for posting that bullentin about the 3.9 cars, but again the post was about 5.3 which he was wrong on.

So, yes I can be an ******* all I want because I like to look out for you guys. The LS4 family.

BuffaloSS

iTrader: (3)

Silver...i think it was a misunderstanding as i mentioned...he wasn't calling YOU out.

EDIT: Yeah...nevermind. He got there first.

Resonance

I just put on my Magnaflow system yesterday. Sure you loose a little low end...but you dont need it anyways. Instead of being able to only use 1/4 of the pedal from a stop without chirping the tires, now I can use 1/3 of it! Heh...really though, I didnt notice any low end loss. I can still burn rubber as long as I want (which is not very long at $250 a pop for tires).

SILVER LS4

If you were looking out for him (or the ls4 family), you could have at least told him there is a bulletin out there, but no for the 5.3's only the 3.9. Maybe you should just try harder at looking out for the ls4 family and not be such an *******, because it seems your having a hard time doing both.