Ok, So wanna start this for two reasons. GM Techs that will reflash a 2.2 to change tire size, update the computer with TIS updates, and flash out SAI.

Also, for anyone who has brought it to a dealer who would be willing to do one or all of the items listed above. Lets not clutter this up with "This dealer won't" Lets just keep it to places that will do the work for us.

TIS Updates Thread:
https://www.cobaltss.net/forums/problems-service-maintenance-69/sps-info-68310/

SAI Explained Thread:
https://www.cobaltss.net/forums/2-2l-l61-performance-tech-45/secondary-air-injection-late-production-2006-l61s-38488/

SAI Solution Thread:
https://www.cobaltss.net/forums/mid-central-107/halfcents-crate-engine-depot-meet-follow-up-66177/

Tire Calculator Thread and Site:
https://www.cobaltss.net/forums/wheels-tires-96/different-size-tire-speedo-calculator-65868/

So here is the how-to for changing tire size and RPO codes.
1. Connect Tech 2 to car and make link
2. Connect Tech 2 to computer and log into GMDealerworld
3. Once logged in you have the option of numerous RPO codes: They begin with Auto or Manual, then ask you tire size, then a choice of RPO codes
4. Choose your transmission, tire size, and then RPO NF4/NT7
5. Upload to tech 2 the new codes
6. Connect tech 2 to the car and upload reflash

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Dealers that will do the work:
Lattof Chevy in Arlington Heights IL., better known as Crate Engine Depot (All 3)
Dealer in Lawrence, Kansas (Tire size)
Dennis Hanks in Ozark, MO (TIS Updates)

 

They'll all do tire size. I'm not sure if they'll do anything else. My local dealer only cleared my lean code I think. I'll let you know if they removed my governer with the reflash.

 

Lattof Chevy in Arlington Heights IL., better known as Crate Engine Depot.

 

Great thread! I don't mean to clutter it up with a question post but what are TIS updates?

 

No worries.... updated the first thread with the link to the thread.

 

I really dont mean to clutter this thread, but i can tell you for a fact not every dealer will do tire size. I went to the biggest one in the valley and they told me they could not adjust for it.

 

I had the same problem.. my dealer told me they didnt wanna chance something happening and it being tied back to them changing the tire size... sounds like they were clueless

 

They can do it since GM offers alternatives to stock wheels and tires depending on the dealership. Not all of them will do it. The dealership in Lawrence, Kansas will do tire size. I only know because I asked the maintenance guy.

 

Cartek in Garwood, NJ - SAI Delete

 

Added How-to on removing SAI

 

TIS updates at Dennis Hanks in Ozark, MO. Just tell them you have idle surges.

 

Correction: Cartek in Garwood can not delete SAI, they don't have tech 2. On the phone they misunderstood me and as soon as I said Cobalt they thought SS/SC and assumed they could use HPTuners. I was really unhappy when I went down there today and they thought they could just connect me to HPTuners after I specifically asked them if they had Tech 2.

 

I was told that Montgomery chevrolet on Preston Hwy in Louisville, KY will do the tire size adjustment. I had asked because I was interested in upgrading to the 18" ss rims and the customer service manager, Doug Kendall, said it would cost about $80 to adjust the tire size in the computer. Not sure if they would do anything else or not but they seem to be very willing to help out.

 

FYI when using dealer TIS, you can only reflash to an existing calibration for a tire size that was available as a Regualar Production Option for THAT EXACT Year/Make/Model

For instance on a 2006 Cobalt LT sedan, the only tire choices available in TIS will be:
P195/60R15
P205/55R16

You will NOT be able to reflash for 17s or 18s

AND this will only be the case for 2005 and 2006 Cobalts- the 2007 and newer will not permit these changes in TIS.

If you have a 2005 2006 Cobalt you want to see what possible tire sizes exist you can enter your VIN at this web-site: http://tis2web.service.gm.com/tis2web
Select PCM/VCM/ECM > NEXT
Assuming the size you want exists in TIS, If youprint out a screenshot and take it with you, it might be easier to convince them to make the changes
A dealer will generally charge at least 1hr min labour for a reflash, unless they were the ones that switched up the wheels/tires

WopOnTour

 

so what do you do?... you go there and ask them...hey since i got a larger set of rims and tires can you reflash my computer to let me go faster??

 

its not letting you go faster.... im simply a better calibrationg for your speedometer and odometer

 

now, if i have my local garage with a GM tech 2 delete the SAI will i still have those codes in my system.. from what i understand if u do a cat delete with HPT the codes will still be in the computer on your car, you just wont throw a CEL... please let me know if this is true or not.. my car goes in on wednesday to fix all 4 of the CEL i have from the SAI

 

technically it will let you go faster.

Your fuel cut off will stop at 120 in a stock lt on 16's, it will stop at 120 (Speedo) with 18"s too, but it will actually stop (compensating for tire sire) around....115? so it will up your top speed a bit. (not INCREASE, but allow you to hit the stock max again)

 

if you reflash your pcm your computer wont even look for SAI. you wont throw CEL's. they will delete the codes and no more will be triggered

 

so than do you think my local garage can do it with there gm tech 2?

 

If they have Tech 2, yes they can do it. Good luck finding a garage with the actual Tech 2 dealerworld software, I've been trying for months with no luck.

 

my garage told me they have the tech 2.. they paid 4500 for the CPU and have to pay 1200 a month for the system updates... i was talking to the guy about it, he laughed when i said i have a code reader, he was like yeah, my code reader will read 400 codes when yours reads 5 and we got to talking about it and how much money it is and **** like that so hopefully they can do this for me

 

so what do you have to do ?....go there and ask them if they have the tech 2 program "?

 

its more than jsut a program, its a whole computer and its very expensive.. alot of places dont have it due to the price of it

 

so it would basically have to be a place that makes good money and has the $$$ to spend like that