Please Help Diagnose My Problem

[PINKED]

Bear with me.. I will try to explain this the best I can. I have had my 2011 SS/RS Automatic Vert since mid April. When traveling at low speeds and upon initial accelleration I get a sputter or hesitation that I can hear through the exhaust. It happens every time when going from 1st to 2nd gear or when the RPM's go just over 1,000. You can really hear it if I'm going up hill. My husband just installed my new Solo Catback exhaust over the weekend and you can hear the same exact sound but it's a lot louder and pronounced now.

I took it to my dealer a couple of weeks ago and they had three different service people test drive it and couldn't find the problem (of course). I drove the service manager in it, pointed out the issue and he said it was normal.

I just don't feel like this is normal. I want to take it back to the dealer but I want to do my own investigating first. I'ts a shame that we usually have to tell the service people what is wrong and how to fix it.

Anyone else notice anything like this?

Thanks for any insight!


**UPDATE**

After reading your comments here and doing more research I'm thinking it is the AFM. So, the AFM has to go! What is the best tune for this? Everything is stock except for the solo catback exhaust.

[anthonyj9h]

if its hesitating there is a tsb for the service department to take a look at the cam sensor ...sometimes they are loose and its just a simple snap try that.....or it might be the afm kicking in and its just more pronounced

[steeleshark2]

Could it be the engine changing from 4cyl to 8cyl AFM? It gets louder with aftermarket exhaust.

[PercyJWellingtonIII]

Take it to another dealer. Run an onstar diag.

[PINKED]

Originally Posted by steeleshark2

Could it be the engine changing from 4cyl to 8cyl AFM? It gets louder with aftermarket exhaust.

I wouldn't think it would be the AFM at such low speeds would it?

[anthonyj9h]

depends on throttle position....if you accelerate slowly and the throttle position is borderline v4 or v8 it could be the computer trying to figure out what the hell you want to do lol

[justa25thTA]

Originally Posted by PINKED

Bear with me.. I will try to explain this the best I can. I have had my 2011 SS/RS Automatic Vert since mid April. When traveling at low speeds and upon initial accelleration I get a sputter or hesitation that I can hear through the exhaust. It happens every time when going from 1st to 2nd gear or when the RPM's go just over 1,000. You can really hear it if I'm going up hill. My husband just installed my new Solo Catback exhaust over the weekend and you can hear the same exact sound but it's a lot louder and pronounced now.

I took it to my dealer a couple of weeks ago and they had three different service people test drive it and couldn't find the problem (of course). I drove the service manager in it, pointed out the issue and he said it was normal.

I just don't feel like this is normal. I want to take it back to the dealer but I want to do my own investigating first. I'ts a shame that we usually have to tell the service people what is wrong and how to fix it.

Anyone else notice anything like this?

Thanks for any insight!

take the service manager on a ride in one of the cars on their lot and see if it does it in their brand new one.

[PQ]

Doing it going from 1st to second is not normal. If, in fact, it is doing it like that.

If it's in a downshift, it's perfectly normal. If it's only at easy exceleration after a constant speed, normal. If it's from a stand still and you first start off really slow and then get into it, normal.

This 6L80E is different than anything I've ever driven. Even tuned it still does weird things.

I'd bet money that it's perfectly normal what you're feeling.

[ravensjeff]

Maybe you need to do the fuse pull since the dealer most likely put in 87 octane gas for your first fill-up.

[chbailey]

this is normal, I had a 2010 and after 1 year got a 2011 and they both do the same thing (both v-6).

[IROCanSS]

Try the fuse pull first.

[PINKED]

Originally Posted by ravensjeff

Maybe you need to do the fuse pull since the dealer most likely put in 87 octane gas for your first fill-up.

I know this is not the case. I was at the dealer when my car was delivered. I was very specific about 93 octane and the guy even gave me the receipt showing 93 octane.

[Russell James]

I agree, I'd do the fuse pull then stick to premium gas. May not have anything to do with it, but won't hurt.

I doubt there is anything wrong. The verts have funky valves in the exhaust that react with the AFM turning on and off. The valves may also be fluttering between shifts when the computer kills the power. There is a bulletin that the noise in those valves is normal.

Does it do it when manually tap shifting?

[PINKED]

Originally Posted by Russell James

I agree, I'd do the fuse pull then stick to premium gas. May not have anything to do with it, but won't hurt.

I doubt there is anything wrong. The verts have funky valves in the exhaust that react with the AFM turning on and off. The valves may also be fluttering between shifts when the computer kills the power. There is a bulletin that the noise in those valves is normal.

Does it do it when manually tap shifting?

It has never had anything but premium gas. I may do the fuse pull anyway just to see if it helps.

I'm not sure if it does it when manually tap shifting. I will try that though and see if it makes a difference.