1998Forrester

1998 Forrester with 180K miles. Started getting a flashing At Oil Temp light (Check Engine light on constantly). About a month ago, the car would rev at stop lights, like it was chomping at the bot to go. This was intermittant, as I would not get it, but my wife would. Two days ago, the At Oil Light started flashing constantly, issues with engine power and consistant stalling when the RPM got below 1200 or so. Took it to Firestone this morning (my mechanic is not open on weekends), and got three diagnostic codes: RT10466, P0102 and P0103. I know the P codes as Mass Air Flow Sensor related, and I have yet to try and clean/check it. I cannot find anything on the RT10466 code. They (Firestone) also said that my transmission fluid was dirty (black) but not gritty. Has anyone else had this similar problem? I can try to work on the sensor tomorrow with cleaner, etc. I have seen some mention of transmission issues on forums and posts, but don't know the extent of what these symptoms could mean for repair and cost. Any help, input, and suggestions would be most appreciated. Thanks!