Got a little story to share with you guys:
Bought a X3 from 5star a few weeks back. Mike was great and got me the tuner quickly and provided the tunes I asked for (I ordered the 87perf and 91perf tunes). The tunes definitely changed the DBW throttle mapping which made the truck feel "jumpier" and firmed up the shifts.
Subsequently, I added a CAI, and asked Mike for revised tunes with stock shift patters as I didn't like how long the truck was holding gears. I drive on dirt roads a good bit between 40 and 50 MPH, and with the stock patterns, the truck would just hold 6th gear whereas with Mike's tunes it would hunt between 5th and 6th.
Anyways, Mike was again very prompt with getting the revised tunes to me. He also advised me that since I was running 93 octane gas, I should use the tuner to advance the timing a couple of degrees.
So this past weekend, I had a great opportunity to try out and evaluate the new tunes. My kid had a hockey tournament in Kalamazoo which is a little over 2 hours away of fairly flat freeway so I topped off with 93 and set out to see how the truck felt.
First I loaded the 91perf tune with +1 deg timing. After about an hour on the freeway, the truck seemed to be running strong. Throttle response was good, and I was happy with the stock shift patterns. MPGs were averaging about 14.2.
So I pulled over for the kids to get a ***** break, and loaded the 91perf tune with +2 deg timing. Immediately after getting back underway, I noticed a good bit of pinging as I tipped in to the throttle. NOT GOOD!
I pulled over again and changed over to the 87perf tune with +0 timing and stock shift patterns. Since it takes a while for the truck to adapt to the tune, I drove the rest of the way with that tune. Seemed to run fine without any pinging. However, the MPG average dropped down to about 13.
For our return trip, I wanted to go with the 91perf +0 timing to try to squeeze a few more miles out of the tank of gas. This is when things started going south!
I plugged in the tuner just like any other time, and it proceeded to load the tune. However, instead of the usual Download Completed message, it came back with some error saying Vehicle Mismatch - very strange I thought, but at least the truck ran.
We got home Sunday afternoon, and my wife took off with my daughter who had skating practice. I had an hour before my hockey game (play in an old man beer league), so I decided to flash my truck back to stock. Plugged in the tuner and selected the Return to Stock option. Followed the instructions, and watched the tune flash just like any other time. HOWEVER, when it finished this time, if came up with a Download Failed error, click Sel. I turn off the key, click Sel, and it shows Error 1016. So I'm thinking - this can't be good! Sure enough, my truck is completely dead and won't start
Disconnected the battery, waited, reconnected it. Tried returning to stock again - same thing. Downloads to 100% and then Download Failed message - truck won't start. Tried re-installing one of Mike tunes, no go there - tells me to return the truck to stock - haha, very funny
Contacted Mike, and while he responded quickly (for a Sunday evening), said that I have to get a hold of SCT after 9am Monday. How's that going to help me get to hockey Sunday night or work Monday morning!?
Anyways, needless to say, I'm not very happy with where I'm at right now, but am counting my lucky stars that the tuner didn't kill my truck en route to KZoo! I can just imaging the world of hurt I'd be in with my wife and kids in a dead truck an hour away from anywhere and a tourney to go to!!!
Moral of the story is DON'T try to update/flash your truck unless you can afford to be without it for a few days