Jump E1-TE1 under the hood on the driver side strut tower. Stick a paper clip in there, then go sit down inside the car with all accessories off and put the key in the "on" position. The Check engine light will blink. You count how many times it blinks. For example:
[] [] [] [] [] *pause* [] [] <== Thats code 52. If your ECU is throwing multiple codes, then it'll be something like this:
[] [] [] *pause* [] [] *pause* [] [] [] [] [] *pause* [] <== This means its throwing two codes, 32 and 51. It takes a while because you have to count them over and over to make sure you only get the one or two or three plus codes. If it keeps throwing one code over and over, or two codes over and over, then obviously, those are your only two codes.
Then again, you only check for codes if your check engine light (CEL) is on. If your engine is idling at 1200rpm, I think your TPS might be out of adjustment. Good luck.