High Idle Issue - 98 1.8t (AEB)

[BPassione]

1998 A4 1.8t (AE

Yesterday afternoon when I was leaving work I started my car and it would idle properly then it would amost stall and then shoot up to about 1200-1300 RPMs then it leveled out back at normal idle then it repeated this process. I never moved the car and it did the for about 3 minutes, so I shut the motor off and waited about 5 minutes and started it up and the car ran fine the rest of the day.

This morning I turned the car on and the idle was sitting consistently at about 1100-1200 RPMs. Then I took it around the block to see if it settled out, it did not, it then started to idle at about 1500 RPMs then after a few seconds it would drop to about 1000 RPMs then back up to about 1300 RPMs.

The car has never done this before and it worries me. The car is completely stock. The coolant and oil gauges read properly.

There is a check engine light on and I am getting it looked at tomorrow. But to me it seems like it could be the any combination on the following: Air Temperature Sensor by the throttle body, the Mass Air Flow, or Idle Air Control.

Has anyone else had similar problems? And are my assessments of the possible causes accurate?

Any and all help is greatly appreciated!

[lordoftherings]

the three things you listed are all prime suspects in that type of situation, id say check the code and the code will come back to one of those.