Reduced engine power
 

I have a 2008 Impala LT with 46xxx miles and last year was the first time I've ever gotten this warning on my car. I brought it to my local mechanic and they said that it was a sensor that has gotten dirty and to bring it in if it ever happened again. It seems to happen when the roads are all slushy after a snowstorm. It happened again this summer but it was a sunny day. Now recently in the last two weeks I've gotten the reduced engine power warning almost every couple days. We have gotten a ton of snow up here in Maine in the last two weeks. I figure maybe the sensors gotten dirty again but this is ridiculous. I mainly only drive in town but limping home at 10mph for 6 miles from work is ridiculous. I've heard horror stories online about people getting it while driving on the highway and I'm thankful I'm not one of them. I'm going to have my mechanic look at it tomorrow but it seems that reading through some thread that it could be multiple things. Just want to have an idea of what could be wrong. I hardly have any miles on the car and bought it brand new off the chevy dealership at the end of December in 2008 so I don't believe I have any type of warranty anymore.

So are you getting a SES light?
What's the code?

Yes that's on. I will have to have someone check it with a code reader.

I heard a common problem is the accelerator pedal needs to be replaced but it seems like it only happens after a snowstorm when the roads are all slushy.

Sounds possibly like ABS sensor related in the front wheels (sensor/wiring)

Turns out I just needed to have the throttle body cleaned.

It happened again this time it was the code P2138, not sure if it was a different code when it was in the shop. I replaced the accelerator pedal position sensor and had the check engine light shut off manually. Hopefully that's the problem but only time will tell!

Hopefully that solves it for you, and it's not some electrical gremlin.