I recently purchased my second Subaru, and it has some puzzling problems.  When I start it up, it revs up to 1,500 - 2,000 rpm for 30 seconds and then drops down to 1,200.  The AT Temp light flashes 16 times, and the Check Engine light is on.  When I shift the transmission into gear and try to drive, it acts like the engine is under a very heavy load.  At first, I thought the exhaust was clogged, but after checking, I don't think it is.  As the car accelerates, it shifts very hard, and when I take my foot off the gas, the car slows down as if it had a stuck brake cylinder (but it doesn't).  Finally, when I stop and shift to neutral or park, the engine still acts like it is under load.  When I shut the engine off, the drivetrain relaxes, and the car rolls backwards a little bit.  When I pull the code from the ECU, it tells me there is a problem with the idle air control valve.  I took it off and cleaned it.  I also tested the resistance on the pins, and they are around 9 ohms like they should be. 
  
Could my idle air control valve still be bad? 
  
What about this transmission problem?  At first, I thought it might be the Duty C solenoid or transfer clutch, but I cannot read an error code from the transmission.  I am using an ELM327 code reader.