Drove from the Bay Area to Lake Tahoe area, which is at around 6,000 feet. On my way up, I was leaving a rest stop, which is at about 5,000 feet, and got the "Engine. Reduced power!" warning. My turbo stopped working. No knocks, pinging, or any other strange engine behavior--just no pickup on acceleration.

I was in Tahoe for three days. I started the car a few times and the error was still there.

On my way home, I had the error sitting there in my Nav display...until I passed the same rest area on the way down. Full performance restored!

I have the K&N CAI filter setup installed. All things being equal, I guess my car didn't like the altitude. My only theory is that MAF didn't like what it was sensing, what with the CAI installed and everything, and disabled the turbo. (That's just a theory--don't ask me to elaborate!)

Anyone else have this happen? Is there impending failure around the corner? My MCS R56 has 90k miles.

 

I live in CO and haven't had this error occur. The only time I've had the "reduced power CEL" is when my resistor shorted on my Alta Recirc Valve. It could be that my ECU has adapted to the MAF readings with thinner air as a normal operation though...

 

Had the same thing happen to me on the way up to Huntington Lake (7000 ft), I was pushing it a bit and it kicked the warning on and it felt like the turbo lowered the psi or stopped. I was up there for a few days and would start the car periodically and the warning was still on. Once I got out of the hills it went away and the car ran fine. I also have that intake.. 2008 52k miles.

Not sure what the deal is tried to get the code but it didn't store it.

 

Please keep me informed on this one as I live in Florida (0 altitude) and get this error frequently on my used 2007 R56 S. Reduces power, then in 5 - 10 minutes it all corrects itself and goes away. This car came straight from the dealer with lots of problems, (I'm in it over $1500 already) with everything from transmission fluid in the coolant system to cracked intake to an error code they blamed on the K&N intake that was already installed!

 

Same thing happened to me in the Yosemite area when passing an RV, big scare. It corrected itself a few hours later when I got closer to sea level. Hasn't happened again.

-m