Seasonal fuel blends
 

I have owned an 06 LT since April 09. Drove down to Treasure Island FL. and back with no problems. In Oct.09 I experienced my first engine light and it stayed on (with me resetting it, from misfire codes) a until spring 10. Then this past spring into summer, it was on maybe once or twice, and was off until my first fill up last week. I am back to resetting it again. So, dose anyone else have any problems like mine, do to Fuel blend changes, I are there any remedies or products that will help?

What octane are you using?

Was wondering the same thing about octane, also if this all comes from the same station/brand. I never have problems like this but I'm also using 93 octane Sunoco, as my 2.4L runs best and gets better mileage on it.

For whats its worth, when "winter" comes around in michigan, I go up a grade to 89. I noticed a few years back that to me the engine seems to run better during the winter months when I use 89?

Seasonal Blends
 

I always use 91 to 93 octane, but mostly it is Mobil fuel which is 91.

I run premium, especially during the winter...notice the cars will run a little better with it. I'm guessing it has to do with the crap they put in for the winter?

I had the same problem. Intermittant misfire codes. They seemed to come up less often on premium fuel, but eventually became a pretty constant.
There's a tech bulletin on it somewhere.
GM changed the design of the injectors b/c of this issue, and issued new ECU calibration files to go along with them.

If you want to fix it permanently, change out the injectors for the revised ones (watch out, they have a DIFFERENT PART NUMBER), and update the calibration files.

Mines been all over the southeast since I bought new. Never had a problem. But if you are having a misfire code, you could also have a bad plug or coil. Get the code read and see what it tells you.

They actually change the fuel blend in certain portions of California from October through January each year. More oxygen additives to reduce air pollution, but it makes my mileage go down on all of my cars. I am glad when they switch back.