New to the forum.....hello.

So, i had the gm stage 1 installed on my 2010 turbo by the dealership. It ran awesome but sounded wimpy, so i decided to delete the muffler.

now two weeks later it went from spinning tires in second and running rich, to slow and and running lean. i took it to the dealership and they are trying to say its because " Lack of backpressure"....

Edit" it hasnt lost any boost pressure either "

Has anyone else had this issue>?

Thanks


ohhh and no codes/cels

 

nope, it's most likely due to poor connection of the GMS1 sensors. I had the same setup for 6 months and never had a problem.

 

do you have an estimate on how many miles you traveled since the muffler delete?

I'm just trying to get as much info as possible.

 

mine is fine on Muffler delete and Stage 1. its also fine with Trifecta tune.

 

Better idea...if they keep giving you a hard time...put the muffler back on and prove that it still doesn't work. Nothing better than throwing a dealer's lies in its face.

Muffler Delete will not change a damn thing on this car (outside of sound). And that's that.

 

yeah if thats what i have to do i will, but i was just making sure.

i was already having a shuddering issues when it was cold, under no load and low rpms, before the muff delete and i told him that. its obviously the install on the kit.

 

just talked to the "Service Director" and he is having a GM Engineer come out and troubleshoot it....thank god

 

tell them to make sure the sensors r soldered and not crimped on.

 

they did the solder and heat shrink and bend the ac tube and blah blah blah......


They still couldn't figure out my skewed and random rich to lean a/f ratio????

ANy ideas? O2 sensor, bad 3 bar map sensor,????


so now i have to put the muffler back on and bring back in.

 

brought it back in with muffler installed and now they called me to say its running normal....... it wont even spin second with tc off??

rrrrrr

 

Typical GM, i have Trifecta tune with muffler delete and it runs great. Dont they know there is no need for "backpressure"?

 

its driving me crazy, it only has 800miles on it and it went from being fast to stock feeling. it only happens when the car warms up to operating temp 180-190. i sware im going to have to lemon law this **** if they dont fix it.

 

try a different dealer.

 

It's a straight through muffler anyway, backpressure wouldn't be lost by removing it.....

 

Agreed. I think it was Hahn that flow-benched all the exhaust components a while back and found the muffler flowed roughly twice as much as the cat, and much more than what the stock turbo could theoretically produce. Since the cat is still in there, I can't see how taking out the muffler could make a damn bit of difference.

 

If you are having crazy fuel trim shifts then you should look into check the Evap Purge Selenoid. Typical Failure