JCW

iTrader: (1)

First off I have ran searches and tried several different solutions but still runs like crap.

So I have 2011 Sierra 6.2L 2wd flex fuel with P1 Procharger, 8lb pulley, Corsa Sport, removed 3rd cat, 89lb Fast injectors and KHP tune.

I did the install myself and drove to KHP to get injectors and then tuned. Now first off truck will hit 8-8.5lbs of boost but surges at idle and acceleration. But KHP did tune in first gear and let out each time at shift so we didn't feel surging, but I did feel surging at idle and he says that's normal. (Its a 500-600rpm surge, that's not normal) On the way home I floored it 1st through 3rd and noticed something didn't feel right and as I let out the SERVICE TRACTION CONTROL - SERVICE STABITRAK - REDUCED ENGINE POWER LIGHTS came on. I limped to side of road and turned off. Waited 30 sec and started up, truck was no longer in limp mode and I drove home. SES light was on and so I pulled codes with scanner. P0120 (throttle body circuit malfunction) I replaced TPS and issue still remains. Surging at idle, surging upon acceleration and then when I floor it for a few seconds the dreaded SERVICE TRACTION CONTROL - SERVICE STABITRAK - REDUCED ENGINE POWER LIGHTS come on with new codes P0068 (MAP/MAF sensor pressure) P0108 (manifold baro pressure). So I check all my PCV and vacuum lines to make sure all are tight and installed according to the Procharger manual and all seem fine. I decided to clean throttle body and Mass air sensor and take for test drive...same scenario everytime. More surging at idle, surging on acceleration, codes etc...It has now done it 4 times.

I have called KHP but he seems to get defensive immediately when all I am trying to do is seek advice and get to the bottom of this i'm not pointing fingers. And he claims his tuning is not the issue. I have no clue at this point....ANY IDEAS?

bud8fan

iTrader: (9)

my '11 did the same thing with the traction/stabilitrac notice and limp mode....there is a fix for it on a thread in here so they can tune it out.

JCW

iTrader: (1)

Do you have an idea what it was that fixed yours?

bud8fan

iTrader: (9)

allen changed my pcm and my throttle body out . I still get the service tc/st message but it does not go into limp mode ..I did see the fix in a thread here and gave it to him but have not been back up to the shop with this truck to tune it out...ill look and see if I can find it again in a thread here.

JCW

iTrader: (1)

I've been reading about guys swapping out throttle bodies for the fix. Some it works others say no change. I did replace TPS but did nothing. I guess I'll give it a shot....might as well upgrade to LS3 or LS7 throttle body while at it.

bud8fan

iTrader: (9)

I was hoping someone with the info would chime in with the answer because I cant find it either...good luck.

George C....

Tune related find another tuner

1-87 chevy

iTrader: (12)

^^^^ iam with him
get yourself a different tuner before you drop money on parts you don't need.

JCW

iTrader: (1)

Who do you guys recommend in the Houston area???

fondupot

Go on the ProCharger website and find a dealer in your area and call around to see who has the most experience with tuning those. That's how I found a local shop who I am going to consider doing my install and dyno tune.