Rep Power: 0

Hi Guys, please help me with my 01 civic sedan. Since I'm in Australia, I think the car is equivalent to your LX model (non-VTEC).

2 Weeks ago the check engine light was on and when I drove it, I could feel that the gearshift was not as smooth as usual and when I let go of the throttle pedal, the engine choked. Idle RPM was pretty high too when that happened. I brought it to Honda and the error code was for faulty air control valve, the guy said it could be the valve itself or the wiring for it. To change the valve would cost me AUD$560 (OUCH!!). My car is not under warranty anymore and it is also due for a major service too so I can't afford both together.

The guy said they never had any 7th gen with my problem before. Can anyone advise me with this? The other thing is, the light is not always on, when I've driven it for awhile and engine has reached its operating temp sometimes light's not on anymore. Last week, it wasn't on for 2 days. This thing stressing me out

Help!

 
Rep Power: 812

It sounds like a faulty idle air control IAC valve. At idle with the butterfly closed, the valve opens slightly to allow the engine enough air to idle properly. Take off the airbox and start the car briefly. Look for a small port inside the throttle body above the throttle plate (butterfly). Cover it with your fingers and see what happens to the idle. If the idle doesn't change, the valve is faulty. Now they don't sell this separately, so you would have to buy an entire new throttle body. Keep in mind they are different for auto and manual drive cars.

Anyway, I searched this yesterday online and found a page where there was a diy on how to fix the IAC for a prelude. Try searching idle air control valve and see if you can find that page and try it out. If nothing else works, get a new tb from a junkyard somewhere. Don't forget to change the gasket when you swap throttle bodies.

fyi, the idle air control is attached to the left of the throttle body and has two coolant hoses attached to it.

 
Rep Power: 0

Thx for the prompt reply
Thix IAC valve, is it repairable or replacing it is the only way? Do u think I should get a 2nd opinion from another shop just to make sure of the problem?

One more thing, if I keep driving the car for the time being, would I do further damage which can lead to something more serious?

Thx man, looking forward to you or anyone's reply.

 
Rep Power: 812

well like I said search online. I know at least one site has a diy on how to repair it. But most shops would just replace the entire tb. Only risk with driving like that is stalling.

 
Rep Power: 374

I had this problem and the idle air valve was quoted at 200 usd for the part. F* that. Grab some throttle body cleaner and go to town on the tb and valve. Carbon deposits get stuck in the valve and make it stay open or closed, and on a manual trans, this reaks havoc by fluxuating the idle from 500 to 5000 rpms constantly. Use a cloth and the cleaner on the inside of the throttle body, and if needed, remove the tb and clean it thoroughly. It should work ok, then just use fuel system cleaner every 2-3000 miles...