I purchased my Z06 in the mountains of NC. All of the performance upgrades and tuning took place at Heintz Racing in Mooresville NC. I drove the car around in the mountains for a little over a week before bringing it back down to Wilmington (sea level) where I live. While in the mountains and on the trip down the car functioned perfectly. After arriving in Wilmington, I didn't drive the car again until the following day. The car started surging at idol, after driving around for a few minutes the idol became normal. Later that day the car was still running fine, but the check engine light appeared. I checked the codes later that day and got a 10 PCM P0106 H code. I cleared the code and had no more issues. I let the car run today and checked the codes again while running, and instead of a history code it was current. After driving around for a few miles I checked the codes again (while running) and there were no codes, and the car is running great. I did a lot of reading on this forum and others about this code and some things that can cause it. I will check on things that can cause the computer to throw this code (vacuum leaks, dirty mass airflow sensor, etc..), my question is whether or not it is possible the change in altitude could have affected the tuning seeing as how the issue never showed up until I arrived back home in Wilmington? And if so would I need to have it re-tuned? (Boone NC elevation 3,300 feet)

 

What kind of mods do you have? First thing would be to do what you suggested and check for vacuum leaks etc.. Is there a cam in the car? If yes, the tune may need to be adjusted a bit/.

 

Sorry, Yes there is a different cam. I have the mods in my signature but I think you have to be a paying member for it to show up...need to do that by the way.....here is the list:
Halltech Air Intake, Comp Cams Custom Camshaft, Kooks 1 3/4 Headers, Kooks Cat'd X-Pipe 3x3, Patriot Performance Xtreme Dual Valve Springs, Powerbond Under Drive Pulley, Spec Stage 3+ Clutch Street Series, Stage 2 IRS differential 3.90, Borla Stinger Exhaust

I don't know the cam specs...I'm going to try and call Heintz racing and see if they can tell me, but it was built in '09

 

Interesting...drove the car back home for and stayed up there for a week with no codes or issues of any kind. I think the vette just doesn't like hot, humid, sea level air.

 

The wife's Grand Prix is bone stock and when we took it to sea level, it shot EGR codes and an O2 code. It occasionally acted like an *** and would stall. When we came back to CO, all is well. I've noticed when my truck was OLSD, the barometric correction factor was way off so it started running leaner and leaner the higher I got. It was perfect at sea level but not happy at altitude.

 

Altitude most definitely has an affect on the tune. Higher elevations typically call for leaner, more timing in some cases. At sea level, less timing and more fuel. Sound like you could be running too rich....and timing may be off. I would definitely have it retuned...

 

No offense, but this reads like you've never tuned anything more advanced than a carb. You understand an engine's needs, but don't realize that computers do all the compensating for you. That is, assuming said compensatory maps are correct.

 

I've tuned several different cars for several years and all as far as I know they are still running strong. Including all my vehicles. But I'm not going to get into that...

I understand that PCMs handle most of the compensation, but it can only handle so much. It depends on how far off the tune is...

 

I have to disagree here. If the barometric pressure map is correct (or whatever algorithm the newer PCMs are using), then the wrongness of the tune should be the same at any altitude from sea level to Pike's Peak. If you have something more, please share. We're not talking about O2 compensation here. That said, on my truck, the barometric pressure map seems a bit off or else my AFRs wouldn't have swung so lean when I got up here. Of course I can't change it on the black box, but that's neither here nor there.

 

What are you disagreeing with? My point is simple, in that EVERY PCM can only compensate so much, before it starts running crappy and throwing codes. Altitude is something to consider when tuning for the most power and efficiency. It's a fact. Again, it depends on the tune, state of the vehicle condition, etc.. MAF curve, LTFT's, VE, AFR's all are critical here.

And of course, I know we aren't just talking about 02 sensors here...

BTW, I've tuned on different kinds of dynos, the track, and the street in different elevations, temps, etc....and the tunes are indeed different. Some more drastic than others.

 

....and mods come into play. The more mods, the more critical a retune is necessary when changing elevations. A stock car will do fine and usually be ok when switching elevations. But when you start modding like crazy, then it can become an issue...

 

But the altitude compensation stuff isn't limited to 5000' worth of change, so it's not like a +/- 10% deal that's "learned", it's instantaneously calculated. My thing is this: if you tune it at a low elevation (thoroughly) and head to a higher elevation, your fuel and spark maps are already written for the less dense air. It "sees" less air is entering and injects less fuel and adds spark advance accordingly. Of course this is the opposite of what the OP is experiencing so it's not entirely relevant. The car was enable to hit the cells it's not hitting at a lower elevation. One curveball I got with my standalone'd Corolla was that I had to turn down the pump shot up here in CO. The ECU is still running a sea level calibration from years ago and is surprisingly close to being right, despite adding cams and a bigger header. Cruise is generally within a few tenths of stoich which kind of supports what I stated earlier in this post. OP, I apologize if I've rambled, but it's been so long have you had it fixed by now?

 

"you tune it at a low elevation (thoroughly) and head to a higher elevation, your fuel and spark maps are already written for the less dense air. It "sees" less air is entering and injects less fuel and adds spark advance accordingly."

You got it backwards. Lower elevation has denser air...

Yes, when you move to a higher elevation, the MAF sensor "sees" less air and will compensate by injecting less fuel...but it won't be an optimal tune. This is especially true, if it has several major mods (heads, cams, supercharger, etc..).

Mostly stock vehicles don't need to worry about making changes...

 

I may be reading these last comments wrong, but it seems like you guys are in the same train just different cars. But to answer the question, no I have not had it looked at yet. it has cooled down a lot outside and I've had no issues since. I will have it re-tuned before summer next year though, and with the mods done to the car (larger cam etc.) that would make sense to have it re-tuned based on what I have read.

 

Absolutely. You'll be happy you did.