Took my car in tonight so they can drive it when its cold.....its in for the second gear shift when its cold the car almost dies when i press the gas.....and also for the 1/2 throttle choppy acceleration...its sooo choppy that my ass moves back and forth in the seat between 2500 and 4000rpm

Really annoying

Hope they figure it out

 

they scanned the car....running LEAN at lower rpm's, then at 4000rpm (+/-) it goes rich

They sent Gm the info so hopefully I will get a response within a week or so

I think they think i beat my car, when in fact I dont and it has done this since day one

 

I hope things get sorted out for ya!

 

Dont let them give you any ****. I have the same bucking bronco affect sometimes. Let us know how it goes

 

never had that problem wid mines. but good luck.

 

Let us know, I have the same issue but it is normally when it gets cool at night and has been sitting, and once coolant temp gets above 100 it want do it anymore

 

actually the dealer is great...they know there is an issue....just hope GM find it

 

I'm working with GM Engineers on this issue, nothing yet. Ask the dealership if they can watch the FTP sensor(fuel tank pressure) during a test drive. Is it varying in its H2O reading; pressure to vacuum to pressure rather quickly. Also, suggest disabling the EVAP system and see if the problem goes away. I wonder if it's the same thing I'm up against.

 

actually I'm having the same problem right now. up to about 3500RPM, the car feels like it's sputtering/and struggleing. then it starts working what feels like normal, after.
that is untill i shift, and again.

I though these were signs of the Cat getting clogged

 

I'm looking at this post and wondering.... Most everyone with issues is a emissions restricted area. i.e. New Jersey, California or Canada. The CA emissions is definately different as well as the NE1 (northeast emissions) i posted a thread on this explaining the lack of power i have with a NE1 emissions vehicle. https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/differences-between-fe9-ne1-emissions-27471/

and here is the dyno run showing the lean to rich condition at 4000 rpm's that snarkee spoke of.....

hopefully yer dealership will have better luck, i personally spoke with the GM techline and they were clueless as to the fuel curve differences between northeast and standard 50-state. I'd be curious as to the results you get with the GM engineers and which emissions each of you have on your cars. let me know if you'd like i can pull the invoices to the cars and see what the build sheet says for emissions. i'm totally saying it's the emissions system.

anyways sorry to ramble and by no means meaning to hijack.

 

they were leaning towards something on the emmisions end as well

i was hoping that stage 2 would fix it but i was wrong....it makes sense as to why a kn drop in filter INCREASED the issue.....now with the stock airbox it isnt as bad, but its still there

 

thats why I'm going to replace the entire exhaust header back, and get the car dyno tuned.
I'm about to finished my second Cat.

 

im ready for a tune

 

hey Mike we should make a visit to Pauls shop soon, get him moving, and gives him a chance to look at the cars

 

im off or the rest of the week man, when ever your ready, im ready, its effin time lol!

 

GO BOYS GO. I really wanna get my car tuned and I have done so much driving in the past month but I will def come down to the GTA as long as its a weekend.

Please post in the tuning thread or pm me if you guys come up with something.

 

for sho!

 

My guess is that it's your intake. Put your stock airbox on and our problem will go away.

 

he did that, still happens on occassion
bone stock ss's are doin this aswell.

 

dont have an intake

 

my bad, took ut the k@n drop in filter

 

You know I am having this issue as well. Mine was going on very minorly at bone stock. Now with stage 2 and the AEM it bucks every now and then, like yours, when cold it is enhanced.

My WEGO goes into the 19's when it bucks then back into the 14-15 ish range. I hope they find out if it is a pump issue or a tweak in the (stage 2) programming.

Let me know what/ if they find anything out.

 

I don't have stage two, mine is still stock tune