i have a 2010 ss auto with the following mods magnaflow catback stage 2 upgrade K&N intake and dejon IC piping.. my car falls on its face or has alot of hesitation when i give it gas. im thinking that its because im in a need of a tune? has this happened to anyone? also it has a loud surge when i let off the gas you can hear it louder with the airbox lid off took it to dealer and they said nuthings wrong

 

stage 2? Do you mean the turbo Upgrade "stage 1" from GM? If so a common problem with then is the wires are not connected properly and the turbo will just not boost. That is a very very common problem with the upgrade kit.

 

If it stumbles with the GM Tubo Upgrade it is one of two things.

One the wires were not crimped properly. Too often the dealers do not crimp them with the proper tools. To fix this some solder the wires or have the recrimped proplery.

or under the load of hard accerleration the lower MAP it hitting the AC tube or compressor. The car then falls flat on its face as the sensore shorts out and pops the blow off valve with a overboost condition, no codes will set. It i will drive normal under lighter acceleration. This can not be seen on a rack as the engine has to be under a load and torqued back. This can only happen on the ground. To fix this they need to remove the front bumper and use fender washers to move the Inter cooler forward. Both of these should be done under warranty.

The Surge sound are hearing may just be the blow off valve. Whey you let off the gas and boost it releases when you lift.

 

could be the intake..... our cars are sensitive when it comes to adding an intake..... whether it's just the K&N filter to replace the stock one or an actually aftermarket intake. if you're not tuned for it, you're fuel trims will be all over the place and makes the car act up.

 

KNN intake should not effect it GM upgrader or not. If anything the GM upgrade should adapt the add on parts.

The questions is what the heck is the Stage 2 he spoke about? This may be a factor since it is a unknown.

 

I agree with these guys. Have the connections for the GMTU (aka "stage" kit) checked out and if it's not that then have the lower tmap checked to make sure it's not hitting on the a/c under full accelleration. Aside from that I'd just advise to make sure the connections on the intercooler piping is tight. On a side note to rallycobalt06: define needing a tune for just the K&N filter element? I have one installed and have had no problems (knock on a redwood!) with the SS's performance.

Later
Allex

 

I also vote the wires with the stage kit. At least have them checked out. I had that problem for almost a year and it wasn't until I read on this forum about the wires did I go in and make the service writer and mechanic check them. They pulled back the electrical tape and said "Oh look at all that corrosion" to which I replied "What part of check the entire turbo system the last 7 - 8 times I was in here didn't you understand?"

Unfortunately I could not get them to solder them but they did recrimp them and so far they are holding up.

 

That is the key. To crimp properly. If they are done right with the right tools the issue is not going to happen. IT just seems there are many techs that just don't do it correctly with the proper tools.

 

Our cars are very tricky and finicky little *****es haha. The car should be tuned with an intake. Any sort. Ask any tuner out there what kind of fuel trims they see on our cars with just an intake. Even though you might not see a difference your car is suffering.

 

thank you once again for chiming in