Reduced Engine Power Warning
 

It keeps coming up on me. It started right before my battery problems. I had also ran it really low on gas before it got bad. Is it possible I just sucked up some sediment out of the tank? Also I read in the manual that it is normally cause by the temp rising too high. My temp has been fine but the it is still coming up. I guess I should just get it scanned. What is the normal problem when this happens? Just a sensor? thanks.

Let try this one in the Tuning section.

Limp-home mode, eh? You have some sort of massive failure (not necessarily expensive, just the computer is concerned). It could be any number of things. I am almost positive that if you scan the codes it will tell you what is wrong. Think about it this way, if you get a cheap-o scanner it is still going to be cheaper than having somebody else read the codes for you, and you will be able to use it again and again. Until you get the codes, I wouldn't even be able to guess. Did you run the tank really low, or did you run it empty? There is a big difference.

Most auto parts stores (at least in my area) have scanners available for rent if you don't want to buy one.

The C5 having drive by wire is very careful that the TAC module is functioning correctly and will not somehow command WOT or get stuck open on its own so even using a mucked up MAF or throttle body can cause a MAF performance error and that would put PCM into reduced engine mode.
Unmetered airmass into the intake can cause this, a bad PCM tune, or incorrect voltage levels can trip this condition.
Also communcation failures such as the PCM cannot talk to the BCM or TAC will also trip this condition.
I'd check for proper voltage levels at the PCM, check for battery acid damage, bad wiring connections, etc but a PCM scanner would really help pinpoint what the problem is.

Thanks guys. I didn't have any damage from the battery acid that did leak. However, this warning happened a while back and now is a current thing. A few days of having my new battery I noticed a few electronics not functioning properly. Then, I got in this morning and click,click,click. Battery dead again. I'm like,"Damn...alternator." I drove it down to the auto parts store and had it tested. Sure enough I'm running at 12.9 volts regular and 12.2 under load. The alternator was scolding hot to the touch and some of the paint inbetween the caseing was peeling. So, I am good to go now. I've found a really awesome price for ac delco alternators. It's even cheaper than gmpartsdirect.com. PM me if anyone is interested.