Hello all! I have a 1997 Honda Accord SE 2.2L L4. It only has 136,000 miles. I don’t drive it very often, but have been lately. About a year ago the check engine light came on. With this came an idle that was constantly up and down after warm up. When I put it in gear, it levels off. Sometimes when I’m driving it will it will all off a sudden act like it wants to stall. I’ve also had it start bucking once. Recently I purchased a code reader, and it gave me a p0137 and a p0505 code. So I now know that possibly the AIC valve is problematic, so I cleaned it and it didn’t help. I also purchased a new AIC valve that didn’t help my problem. I didn’t do anything yet with the O2 sensor code. Could these two code problems be acting together for this check engine light/ idle problems?

 

The P0137 is for the heater circuit in your secondary O2 sensor, which is the sensor in your catalytic converter or past your catalytic converter.

The P0505 is what you need to focus on. You cleaned the IACV, but you should also clean the FITV and snug up the internal screw. There are some youtube videos on how to do this.

 

Removed and cleaned the FITV and It already sounds like a different car! Idle seems normal. I cleared the code and now my fingers crossed that it stays this way. Thanks for the tip! I really appreciate it!!

 

Thanks for posting the results.

Glad the idle improved and hopefully resolves the issue.

 

Drove it for about 10 miles for the first time since I cleaned the valves, and when I put it in park, the idle was instantly up and down, up and down. Any thoughts?

 

I had strange idle issues years ago when I replaced my FITV, so I would reset the ECU.

Try pulling the backup/radio 7.5 amp fuse in the engine bay fuse box for a minute. Then reinstall the fuse. Start the car from cold and let the engine reach operating temperature from idle.

 

For it to properly re-learn the idle, it's important that you start it from cold without touching the accelerator pedal. And let it warm up completely without touching the accelerator pedal the whole time.

 

So I pulled the fuse and then let it warm up from cold. Then I turned it off. Then, the next morning I started It till warm then drove it for above 5 miles and when I put it into park it started idling up and down again almost instantly.

 

Just to go back to basics & not take anything for granted...
Have you checked for things like vacuum leaks? How about the base idle setting? Here's a thread with a bunch of things to check.
https://www.hondaaccordforum.com/for...e-speed-38734/

(I was going to suggest the IACV might be bad even though they normally just need to be cleaned. But you've already replace it, right?)