Coming back from fishing last night the check engine light comes on. I ran the code this morning and it said "improper gear ratio 4th".
I just did the transmission filter a few weeks ago, so I decided to check the fluid level. It is fine, and I topped it back up again.
Also, I have just done the tires this fall with a set of Dura Tracs at 265/75/16. So the tire size has changed. This seems like an odd code, any suggestions? Don't Worry? I had it cleared and have driven in 4th many times since and it is fine.

 

That is a MAF code, clear it and see if it comes back.