Long story short...Installed a Hahn 3' catless downpipe and was very happy with the gains (butt dyno) and sound improvement. Turbo seemed to spool faster and gained some power up top as well..loving it. Had front cover gasket replaced by Cevy dealership for small leak, get the car back and the gains are gone! car feels slower than when I dropped it off. Anyways I was not sure what was going on so after some searching I reset the ECU and VOILA the gains are back. Everything was good for about three weeks or so and now it seems that the car learned down again!. I will not be tuned other than GMS1 until warranty is up. Any input, advice, questions, flames for being a noob, are all welcome.

P.S. HHR SS, 11,000 miles, GMS1, Forge BPV yellow spring.

 

Supposedly the GMS1 does not "learn down". Maybe they secretly switched you back to stock.

 

Welcome to the club, you are only the second one I have heard of. My little Christine does that too. Vince, Mr. tune wizard says, it won't do that, but mine does, it even learns back His tune. Reset either the tune or the #41, back to full race, for a while. Sorry I cant tell you the fix for it, yet. Does yours run like super car, right after a mod, like boosting 26+, till you start it the next time ?

I am waiting for bread fan to get really smart as a tuner, and see if he can figure it out, I have thrown money at it and it still learns back, reminds my of the cute kid on the Capitol One commercial who don't want 50% more money, stubborn.

 

"Butt gains" are impossible to measure, verify or fix, since you don't know what you gained or what you loss. If you have no trouble codes, theres not much anyone online can do for you.

 

I dunno. I might have to take a micrometer to that dent behind where my butt sits since I turned up the boost.

 

Sounds like its time to invest in a gtech
http://www.youtube.com/watch?v=mmfwg...e_gdata_player

 

Thanks for the input guys...I think I am going to have the dealer check for stored codes. I will try to get them to reflash the GMS1 tune as well. I WANT 50% MORE

 

Chevy Mgr,

True, except you know if your smoking the tires in second or not.

I've gone through the same thing as SS fan. A reflash brings it back to over 25lbs, then a few days later down to 21 and butt or not you can see it on the gauge.

I just think the software on these cars, especially the torque management is overdone, or better put, not really finished, especially for the Stage 1 upgrade.

I know the torque management has to be hard on the trans and complete drivetrain, with that abrupt on and off take off.

If you blast off the line in comp and launch control (auto) the tires light up, grip and it's as if someone turns off the key (yes I've had the intercooler moved forward to clear the sensor and also added the TTR still top motor mount).

The the motor blasts off again sometimes with the same result until your up to about 50 ot 60 mph.

I don't see how that type of control protects anything.

Consequently my Impala SS with traction control off works like any car. From a standing start you nail it the tires spin, they grip you go.

Unless Traction control is on, then it acts just like the HHR SS.

IMO

R

 

Even though I changed out my entire engine harness and added the CED plug and play harness....it's still unpredictable on how it runs. Sometimes it runs great...sometimes it runs like poop. Almost wonder if it had something to do with my tranny...because if I throw it in "I"....and max out the RPM's...it runs great each time...producing all kinds of boost....kinda weird..

Then again...I still need tuned for the ZZP intake...because it's making the car throw the P0101 and going into limp mode every once in awhile..