Rep Power: 0

having some problems with my car. i got in to go to work and noticed that my car would not come down from the 2000 rpm mark.when i stopped at the red lights it would jump from 1500 to 2000 rpms like it was camming out or something,but while i was in motion car ran fine.as soon as i got to work my emission malfunction indicator came on. so i checked the manual and it said to check the gas cap.it looked ok to me so i put it back on till it cliked 3 times. i took it to autozone for them to hook the engine scanner, but it did not throw any codes.not sure what is going on ,does anyone have any ideas?

 
Rep Power: 231

weird that it had you check the gas cap...

 
Rep Power: 0

first thing i would check for is a vacuum leak somewhere

 
Rep Power: 282

check the brake booster vaccum line to see if its disconnected or has a cut in it. next check to see if the throttle cable is missaligned on the throttle body. if tis equiped with cruse control check that cable also. next, turn the car on and let it idle. look to see if the throttle and/or cruise cable to see if it is tight at the throttle body. if none of this is the case then the throttle position sensor has malfunctioned. they are a common failure for 7thgen civics.