Long story short, i have had my car at the dealer for 3 times for 1 specific issue. The car is misfiring really bad, mainly for the first 15 minutes after i start driving (the engine could still be warm, but it happens more after it has been sitting for 10+ minutes). I dont remember the codes the dealer told me the car was throwing but it was about 9 codes. It all started after in got the dealer to install the GMPP stage 1 kit for my 09 ss. The wires to the sensors have been checked and they look good. And the dealer has replaced numerous other parts that i will have to list later when i get home.

When accelerating (maybe 30%) it will sometimes bog down a ton and just start bucking. If i have my performance display set to the A/F gauge, i see the car running super rich (maybe 1:9.5-10.5). And also, sometimes when im at a light (or just starting to drive) there is some issue with the by-pass or recycle valve where it will flutter. It sounds like a turkey and its really annoying because even under hard acceleration i never get past 6 psi boost and the car is dog slow.

My issue was supposedly escalated by GM and reviewed by some of their techs, and they are blaming it on the hahn cia intake i installed. After an extremely rude rep telling me that even if i returned the car to stock and the issue still occurs its my fault, i called the dealer again to tell them the issue wasnt resolved. the GM rep told me that the dealer blamed it on the intake and wouldnt service my car, but the dealer never said such a thing.

Anyone have any suggestions?
Im going to put the stock intake back on tonight but if that doesnt solve the issue, it looks like GM is trying everything they can to give me the shaft on this one.

 

Go back to Stock and take it to another dealership and see what happens.

If they refeuse to honor your warranty, request that they put something in writing as to how the Intake caused this specific issue. Until they diagnose the exact problem, there is no way that they can say the Intake caused the problem.

 

^^^^^^ BINGO. dont let them push ya around... just go dealer to dealer if ya can til ya meet a service manager with a brain who gives two ***** about their customers... it's what i did to get my rear brakes warrantied.

 

You really don't think that your Hahn intake,in which you are not tuned for,couldn't be doing this? You did read the intake sticky right?It is more than possible it IS your intake,again,which you are not tuned for.

 

thats the reason im asking it here, to see if anyone has the GMPP stage 1 with an intake and has had any issues.

good job about getting the brakes cobalt_daddy. i had an issue with my rear brakes wearing super uneven and the pads not gripping the whole rotor. and they were replaced with no cost to me.

is it possible the air sensor that is inside the intake is in backwards. that would be a huge screw up on my part if thats the case lol.

no matter who's fault it is, that bitch that called me from GM had no excuse to just blame it on me and hang up pretty much. Im glad to see they are so willing to help their customers.

 

As for the sensor backwards,it's unlikely.The Hahn by itself untuned will cause misfires and cel's.When I would turn off my tune when I had the Hahn on my car,it would sometimes misfire when I got on it.Disconnect your battery,put the stock airbox back on and you should be rid of your problems.Or get someone with HPTuners or call Vince at Trifecta tune on top of GMS1 and tune for your intake.Those are your 2 choices.

 

check the vacuum line by your MAP1 sensor on the lower charge pipe...

See if the plastic stem the vacuum line sits on is snapped off. It will make a pee-hole sized leak but enough to cause your car to run retard rich since metered air is escaping somewhere in your system.

It also explains the low boost. The lower charge pipe is one of the biggest weaknesses in the 08-10' SS.

Get back to us after you check that. I had your same issues on my stock tune settings and that was the problem both times happening. Im betting your fuel trims are retardedly negative as well... do you have a scan guage to monitor the Long Term Fuel Trims? I bet they are -20.0 by now. That would also cause the car to be studdering on acceleration.

 

Not sure why the stage kit would take off the 'learn down' feature to let mods actually have an effect on your car, but turn on the CEL.

i'll find out later tonight if the intake is the issue

and to CudaJoe.
the low boost pressure only happens about 10% of the time while im driving the car. arent the recyle and by-pass valves electronically contoled on this car? if so, its got to be an electrical issue. Im thinking its not consistent enough to be a mechanical issue.

 

In your situation, its not the intake. What you described sounds like a boost leak. The GM Techs have no idea where to look. They get stumped on this everytime, lol.

The first time this happened to me I was able to hit 13-14psi pretty easily but then it would start to stutter and drop to 12 psi if I tried to hold the throttle through the whole rpm. It almost appears as if your boost is fine but try doing a WOT in 4th gear and see if it steadily holds boost and where it holds it. Chances are your car will go nuts after you let off the gas and you wont see the same boost you were seeing before the problem occurred.

Everything is determined off the AFR ultimately.. your stfts and ltfts are controlled by it, your amount of boost is controlled by it. Yes its electrical but if you get wacky AFR, your gonna get wacky Fuel trims, and finally wacky boost. You wont see the wacky fuel trims right away, they have to get wayyyy off before your throttle/boost starts getting effected. Then it depends on how you drive, if they go way negative from you going into boost, they can come back down if you drive the car gently and out of boost.

The AFR is measured by the O_2 sensor on the up-pipe (before cat) it checks to see how much O_2 remains after combustion and gives you an AFR, and Emmisions is measured on the O_2 sensor on the downpipe. It determines how much unburned fuel and enviromentally hazardous gasses have been catalyzed by checking O_2 content after catalyst.

 

im still seeing the same boost pressure (~20-21)
but yea, sometimes if im in low rpm(2000-) and say 3-5th if i do 75%-100% throttle and let off quickly, i run super rich again and my car jerks. its a pretty easy way to set off the CEL after the dealer clears it and says nothing is wrong.

all of the suggestions are great and i really appreciate it, keep 'em coming!

 

Okay im still going with boost leak :p lol.

 

There have been a lot of problems regarding fuel trims, boost leaks, and boost control systems failing.

You really need to monitor your fuel trims and see if there is a big change in trims. Of course do this before and after the intake is on. You will be surprised how bad the intakes are and you might get lucky and solve a problem that you didn't think existed. I.E. a boost leak that was masked by the crappy intake.

 

I KNOW, I had my K&N SRI for a few months and then "My Problem" started happening... everyone swore up and down it was the intake.... I kept telling them no it wasnt, lol. I put the stock intake back on and bam! What do you know!!!

The problem still exists

I had a boost leak on my lower charge pipe. My fuel trims got retardo negative and I didnt notice any issues till they reached astronomical numbers like -25.0 ltfts

 

Yeah put the stock intake back on is the easiest way to find out if its the fuel trims. Like someone else said before my car was tuned for the hahn intake and the long term fuel trims were at -20. So 100 percent the untuned intake

 

so im not a car expert by any means and i dont know some of you guys lingo. like fuel trims, stfts, ltfts, and WOT.

Cuda, i cant see my negatives because i have a performance display not an analog gauge, so i can only see positive psi.

stock intake actually seemed to make the issue worse when driving to work today. no matter how much throttle when in low rpm, the car would just buck and stall, and fantastic loud clanks under the hood when the car would jerk. its too humid outside for me to want to look for a hole in the lower charge pipe. and besides, im still under warranty

 

http://www.ross-tech.com/vag-com/cars/fuel-trim.html

Here's alittle info to help you cross the lingo barrier ADD TRIM in that website means a positive fuel trim. Negative is the opposite.

fuel trims are not vacuum/boost. The RPD does not show fuel trims, nor does it show vacuum. It only shows boost, and AFR and some other stuff...

Bring the car in to the shop and tell them you suspect a possible boost leak somewhere, a friend told you it might be the lower charge pipe. FYI- the lower charge pipe is on back order, expect the car to be in the shop for 2 weeks. or buy the ZZP lower charge pipe and put that on instead.

STFT's - SHORT TERM FUEL TRIMS - measures the small changes made to the fuel added in units of PERCENT% (small changes made every second litterally) example: -8.0 means removed 8.0% of the fuel that is normally added at that rpm and engine load. STFT's bounce around. Removing fuel tells you the car is running rich.

LTFT's - LONG TERM FUEL TRIMS - measures the average STFT's over period of time and is used by the PCM (car computer) made adjustments to the AFR.

AFR - Air/ Fuel Ratio - exactly what it sounds like.

LAMBDA - the change in AFR from what the AFR CMD is. example: AFR reads 14.2; AFR CMD is 14.69 so...... 14.2/14.69 =~ 0.96 Lambda cars running rich.

AFR CMD - The AFR that the PCM (car computer) COMMANDS at the given RPM and engine load.

Using this knowledge plus the codes you've thrown will narrow down the suspect problem. If you throw a p2xxx number for car's running rich. It means your losing air that was measured at the MAF before it meets the cylinder. The measured air gives the car the number it needs to determine the amount of fuel to add. if it dissappears, the car wont know it and still add too much fuel.


Hope this helps some. Im no expert either. but I have a tiny understanding. lol.

 

thanks for the help cuda.
i read quite a bit about people having issue with flutter after the gm stage kit and a crappy install of the lower sensor. possible a cracked manifold or leaking charge pipe.

any idea where to get a good scanner ?

 

just put your stock cai on and go to a different dealer.. they didn't black book you or anything.

 

Im using an Aeroforce interceptor with the ZZP A-pillar. They had a deal last year during black friday

I got the A-Pillar for $41 and the interceptor for $175

 

its deff. bc of your intake, its screwing the MAF tables causing your car to run the crazt AFR your seeing. **** the dealer, get a real tune from a good tuner

 

yeah, but he sees no change... he's back on the stock airbox,

 

ahh, i see.... Deff a leak somewhere...after you get that straigtened out and go back(if you go back) to CAI, get a real tune