Can't fix high idle problem

[Martin1971]

So I've checked the connector and wiring a bit down the line but don't find any fault. Any new ideas are welcome... Thanks

[MetroMPG]

I would have checked/replaced the COOLANT temp sensor & wiring before the intake AIR temp sensor.

It likely has a bigger effect on idle speed via the computer.

[Martin1971]

Thanks MetroMPG

[MetroMPG]

Another thought: I wonder if a stuck-open thermostat could cause this? Coolant not coming up to temp.

[petrified.rabbit]

It could be the thermostat, but it wouldn't it idle normal at first and then climb as engine warmed/didnt warm..?

Did you check all the typical issues, like torn intake boot, vacuum leaks, etc?

[Martin1971]

Hi guys. Thanks. Yes, I looked at the vacuum tubes today, don't see any leaks. Tested with air in a tin and fine spray water.

[Martin1971]

Battle to find vacuum problem. Must admit, I lack experience in this department, but what I've checked doesn't lead to a vacuum leak. Can this be an ECU problem perhaps?? Thanks

[Martin1971]

Okay, guys. Today with the high idle I had the car checked out again with the diagnostic tool - no error. The technician and I were talking around solutions and we hit the Cat converter with a hammer and emediatly the revs dropped. Was fine with a 10km drive and then high idle back again. Slam the cat again and back dropped the idle. My question now is, can a clogged cat cause high idle? Wouldn't it rather cause poor idle?

[Eddievee]

Okay, I replaced the air temp sensor, air control valve and tps sensor. I've cleaned the throttle body a few times. But I must admit, I didn't remove it. I just loosened the air intake and sprayed the intake with carb cleaner and wiped with clean cloth.

Hi did you ever fix the problem? My 2004 aveo has the same problem

[Eddievee]

I would like to know if you found the solution to your problem