WTF!?!? Overboost problem again!

[Shed]

Quick briefing on problem.

01' 75K on it, airaid intake, 4" magna flow. Throwing overboost code while towing on average highway grades. Does not do it on every grade, and the grade does net seem to matter (steepness).

Dealer says it is the aftermarket stuff and wants to put it back to stock, and that "will solve all my problems". I argue that I bought the truck with $1K worth of better equipment and I want it. Plus it gets more power and better fuel economy. Chevy/dealership STRONGLY disagrees.

Many members here have said on 02' reflash would work, and has worked for some. The dealership says this is impossible unless they could find the exact truck in an 02' and give the computer it's VIN. They say all trucks are different in minor ways and a reflash needs to be specific to a VIN. They say they plug the truck in and it "talks" to Detroit and they do all the reflash. Is this true or B.S.?

I know I donot have the only truck with this problem, there have got to be hundreds if not thousands that have done these specific upgrades (intake,exhaust), why are they not having problems? Or how did they fix them? I know JK will say come talk to me and I will make all of your problems dissapear! Thanks JK! I do want to do a custom tune from JK but just dont have the cash right now. Plus now it's getting to be a pissing contest between myself and the dealership.

Thanks for any help! Shed

[DmaxMaverick]

Your dealer is mostly correct. By installing the intake and exhaust, you've unlocked some of the engine's potential. Problem is, the computer isn't seeing what it wants to see, and throws a fit. If you install the OEM intake/exhaust, the overboost will very likely go away, along with your little power/economy boost, but the PCM will be happy again.

Your dealer is also correct, in that HE cannot reflash the PCM w/o a VIN from a near exact 02 truck. HE cannot. That doesn't mean you can't clone the PCM of a like truck, then enable/disable the effected/different features. Ideally, JK's (or perhaps others) reprogram would be best. If he says he has the answer, believe it. It's also more likely to cost you much less to go with an aftermarket programmer, like JK, than to deal with the dealer's shop labor rates. The bottom line with this is your dealer is not really the one to do the mods you need. There are some dealers more eager to accomodate these issues, but GM's general policy it to stay away from them. Anything other than OEM is on the independent dealer, and GM won't support them. Most dealers won't discuss the matter as far as yours did.

[Shed]

Dmaxmaverick,
I agree, I think I'm just reaching for something that is'nt there. I agree JK is the best option. Tried to get Chevy rep to admit I made the truck better/more efficient but he refused. I think that's what got me all worked up! Thanks for the reply. If anyone else has 2 cents they want to put in please feel free! Thanks again, shed

[mark45678]

Back in 2001 GM had a reflash for some small problems like cruise control down shifting to easy , engine codes caused by the block heater and a warm start and over boost codes. if your truck has this update done you poss have a differnt problem. Do you know how high the boost gets on your truck , my 2001 with a 4" full exhaust and a drop in aircleaner with my hot juice set on level 4 would easy hit 32~34 lbs of boost. Never once did it set a overboost code and it spent most of its time at 0-1000' above sealevel ( some time I would tow into the mountains that crested right around 3500'. If you dont have a boost gauge that is accurate to 40 lbs its hard to say where to start but I would look very close at the wastegate first.

[DmaxMaverick]

When we start using add-on performance enhancers, you need to understand how they make more power, and still keep the PCM happy. Most of the time, they make sure the PCM sees what it wants to. In the case of the Edge, the PCM is lied to, which results in more fuel, boost, and adjusted timing, but the PCM is oblivious to it. Your boost may actually be over what is acceptible by the PCM, but it doesn't see it, so it's happy. With OEM programming and no add-on enhancer (like Edge), an overboost can mean several things, some wrong, some not. This is also the problem with damaged engines. If the PCM can't see a problem, it has no way to counter an issue that can cause damage. This is why it is so important to have gages with mods so we can be the watchers. Remember, the PCM assumes all the equipment is still OEM.

[Duramaster]

Shed,

I am a technician at a GMC dealer in Portland, Oregon and I am more than willing to give you all the info you need (all that I am capable of). So let's work together on this. First off, what is your vehicle VIN? If I have the VIN I may be able to tell you what calibrations are available for your truck. Second of all if you take the vehicle back to the dealer and tell them that the engine "surges" at times, they may reflash the pcm. I do believe that in 2001 there was software to address that complaint. I reflashed many DMAX pcms for the surge complaint. The software usually didn't fix anything, I usually ended up having to replace the regulator.

The other issue here is that your truck is out of the 5 year 100000 mile warranty and will probably be out of the 7 year 200000 mile injector warranty?