Doomtor

My cas has been runnnig rough lately. Runs fine on idle, but it will sometimes go very rich and almost stall when releasing the clutch in 1st. Goes to like 10-11 air fuel on my wideband. I also hear the bypass valve having a hard time and opening / closing for no reason. Then I'm on the highway, at let's say 65 mph and same happens it goes rich for a second, engine sputters and I hear bypass open / close. I am not very familiar with misfires but it feels like it's happennig. Car kind of wants stall when it happens and it feel it running rough as it happens.

Basically all is fine on WoT, but it runs like crap some other times. It started doing it a few weeks ago but I ordered and got replaced the purge selenoid and the bypass valve selenoid. Hasn't changed anything. I may get it to the dealer as it's getting very aoonying. Any idea on what I coud be? Spark plugs are OEM ones and they have at most 15 000 KM they were changed recently too.

Dunno what do do my mechanic will scan it tonight and try to figure out what's wrong with it. If he can't find it I may take it to the dealer, but at the price they charge I am trying to avoid it. If I run into problems I may just put this thing back to GMS1 and remove mode and callit a day.

I scanned it yesterday and it shows code P2261.

Any help would be welcome.

Thanks.

Chevrolet Cust Svc

Was your mechanic able to find anything for you last night?

Best,
Sarah
GM Customer Service

Doomtor

He just scanned it last night for code. He said he was going to look into this over the web and then we may try to fix it over the weekend. Curiuosly, everything seemed fine for my drive yesterday and this morning... Will keep you posted on what we can find out. It's surprising though, as it has been doing that for a few weeks already. Gotta love those intermittent problems!

Chevrolet Cust Svc

Oh no! Intermittent problems are pretty special!
Hope everything goes well over the coming weekend,
Sarah
GM Customer Service

Maccoy316

iTrader: (1)

Anything else happen with this issue? I'm starting to run into the same problem, it's running rich and almost dies at times during idle.

slapbetcommissioner

iTrader: (3)

I have been having the same issue and was getting P2261 before as well as p0236, and p2178 (found out the valve breather hose was cracked and then broke clean off of the intake side) that being fixed stopped the p2178 and p2261 codes from coming up.

I still continue to get the p0236 code rough idle random richness and low boost/ almost no power at times.

I got p0236 codes last summer as well as p2261 when i installed my K&N SRI ( I Also have gms1 and 3" hi flow catted dp)
My symptoms were the follwing;
-crazy fuel trims
-Very rich afr
-low boost at times (wont go past 1-5psi on occasion)
-and sometimes the BPV would just start "stuttering" and pissing out boost repeatedly.
The problem would just randomly pop up for short periods of time and i figured i just needed to be tuned for the intake although my fuel trims were mostly BETTER than my Stock airbox and the problems were just random.
I attributed it to the intake and when i put my factory airbox on in the winter it seemed to fix it... all winter i hardly went into boost (no traction lol) so i assumed the intake was at fault.. Spring comes...summer tires back on and back in boost.... WAM Same **** all over again...
The difference is this time its with the airbox... after fixing the breather hose i mentioned earlier it is clear it is the same issue i was having with the intake just not nearly as loud and obvious as with the SRI. That makes me happy (sad i know) but its official that it is the GMS1 sensors at fault. It all makes sense especially with this little tid bit
(read the lower part just after the lower TMAP tips it describes the EXACT issues i am having as well as you)
I am assuming that you still run the GMS1 sensors with the HP tune right? this would still apply i believe.

Now that i have it narrowed down i can take it to the Dealership and actually point them in the correct direction and not get "could not repeat issue" not to mention CED is a GM dealership so its not just random SS.net folk lore im brining to them!

19212670 Cobalt, Solstice, HHR Stage Kit 19212670

I have done allot of reading in the past about the lower sensor wiring and what not being an issue as wella s a badly seated TMAP sensor but i just wanted to find a legit source to bring to the table.

Hope this helps

Maccoy316

iTrader: (1)

Ya I've done some reading and figured it was my GMS1 sensors. So what will the dealership do about this issue though? I've brought my car in and brought up the sensors being the issue and they gave me the typical "we'll have to take a look at your car and determine if that's the issue". Even though I know it's the issue....

slapbetcommissioner

iTrader: (3)

I am yet to cross that bridge.
I would send them that link (as its s gm sight tecnically)

Chevrolet Cust Svc

Maccoy316,

I can understand how the diagnostic process may be frustrating if you're confident about what you believe the core issue is. Thank you for your patience in working with us - our technicians do need to check things out to make sure they're repairing the correct component(s). If I can be of any assistance, please don't hesitate to get in touch.

Best,
Sarah
GM Customer Service

slapbetcommissioner

iTrader: (3)

Glad to see there are people around to keep things posative and give us some backup!

Maccoy316

iTrader: (1)

Only problem I have with them looking at everything else is the time. Paying the hourly rates for them to poke and prod at the car when all I want is for them to fix the one issue I'm having so they aren't racking up my bill. I dont have a warranty as my car has too many bolt ons. Heck I took my car in when I heard something iffy with my suspension. After a few hours they called back and told me "whoever installed your turbo did it wrong and it voids your warranty" M***** F**** its a turbocharged cobalt look up the vin. They then tell me they'll call me back in 20....2 hours later they tell me its the intercooler. So I go down there and get my car back because I'm already tired of the BS. I find out my sway bar came loose. I'm no technician but it's sad when I know more about my car then GM does.

Maccoy316

iTrader: (1)

Hell it even says 2.0 TURBO right on the top of the motor when they open what is called the "hood". Sorry end of rant....for now.

slapbetcommissioner

iTrader: (3)

Wow. Did they change your supercharger oil and put a smaller pully on while they were at it. You need a different dealer

Doomtor

Thanks for the reply. It should help. Car's still doing it, at times. Was planning to remove the forge bypass valve to find out if it changed anything. After I read your thing, do you think I could could go back to the stock sensors and that'd solve it?

slapbetcommissioner

iTrader: (3)

If you did go back to stock sensors you would need to be tuned for them. It would likely be easier to have the lower sensor re installed and protect the wiring with something.