I have a 2000 civic that will continue to accelerate even when not pressing the gas pedal. However, it only does this when the vehicle is warm, like after it's been driven like 20 miles. Otherwise it doesn't do it on short drives or after it's cooled down. I have cleaned the throttle body and intake manifold as well as the iac valve and the gunk around the throttle cable, but the problem still continues. Any suggestions?

 

Adjust the throttle cable to have some slack.

 

I don't feel like this is the problem because it only does this after the engine is warm, but I'll loosen it a little

 

Any CELs?

The only reason the car would rev with your foot off the pedal is if unmetered air is getting past the throttle plate. That would only be caused by a vacuum leak near the intake manifold, or your throttle cable being too tight. Since it only happens when your car is warmed up, I would start going over ALL of your vacuum lines with the proverbial fine toothed comb to find the crack or pin-hole that might be opening after those vacuum lines have warmed up and become more flexible.

 

I have 2 cels o2 sensor and knock sensor

 

Unrelated codes, then.

Pull your codes again, just to verify nothing new has popped up.

 

just pulled them

 

Then unmetered air it is.

Next time it does this, turn the car off, and completely disconnect the throttle cable from the TB. Does that fix the problem? Have you fiddled with the small stop screw on the TB? Is your car completely stock?

 

the boot on the throttle cable is broken would that cause this?

 

As long as your throttle cable isn't taught, it shouldn't.

 

Big vacuum leak possible?

(cracked / broken hose or plastic fitting?