Thanks for all the input guys....

One point of clarification - the surging happened on the original factory tune. Since I had the dealer reflash the the truck and before I installed the Diablo tune it did not happen any more. It would seem that the original dealer tune had something to do with it ...

Gentlemen,

Just as clarification I have had this problem when cold on the original factory tune, the original factory tune with the Diablo and the original factory tune with the Diablo modified. Since the reflashed factory tune was installed I have only had the problem when I installed a heavily ...

The MAF sesor has been cleaned recently along with cleaning a re-oiling the K&N Filter. I am resonable sure that that is not the problem.

The trailblazer does not have a dual exhaust. I will check to see if there are two O2 sensors. I am pretty sure there is.

At idle there is a difference between ...

OK Here is an update:

Running Diablo tune with K&N Intake:
LTFT at idle = 0% +/-
LTFT at cruising = 17% +/-
No surging at cold low throttle

Running Diablo with LTFT adjusted by -15% and K&N Intake
LTFT at idle = -15% +/-
LTFT at cruising = 1% +/-
Surging happens at cold low throttle

Running ...

I am heading out this afternoon and will try the Diablo tune again...

I am fairly confident that there are no exhaust leak or intake leaks. Although I am not sure how to double check this.

I do know that the K&N intake removes a substantial "neck down" in the original intake tube. I believe this is what causes the big jump in air volume and hense the leaning ...

It seems pretty quick after the install. Maybe I will try and install again and test again today.

FYI - I do have a K&N intake installed which has a very big effect on the leaning the truck out. Using the Diablo Redux I have had to adjust the LTFT as much as 15%.

Mike,

Here is an update on my situation.

I restored the truck to factory tune and the dealership reflashed the tune with a new update.

I tried to load the Diablo back in and it did not recognize the truck.

I upgraded the Diablo to the latest version and then uploaded the Diablo tune and actually ...

I guess Diablo was just bullshitting us this whole time....

Very sad....

For the love of Pete......Can't you guys just finish this.

Or maybe I should start this....

Dear Team of Experts,

I have a 2006 Trailblazer SS. Ever since I have owned this car I SOMETIMES get a surging effect when pulling away at low throttle. The surging happens almost only in first gear, and mostly when the car is cold.

I have heard of many different explanations for this situation ...

now were talking....

evadllig 6

Bump

Page 50.....for Christ's Sake