I've had an on and off problem for about a year where my 1997 Civic Hatchback MT will idle at very low RPMs (100-200) when I put it in neutral waiting at an intersection. It mostly happens after I've been driving for a while, like on the highway, and the engine is warm. If I give it gas while in neutral it revs up fine but drops down very low and almost stalls and will stay there until I start to accelerate.

It starts up fine and idles smooth normally, except once in a while like mentioned above it will act up.

I have a short ram air intake with a cone K&N filter, clean (could this air intake be the problem?). New fuel filter, new oil/filter change, new spark plugs and wires. I did get a MIL light that won't go out the other day. Autozone computer test says its P0135 - A/F Sensor Malfunction, BUT, I don't think this is the problem because this low idle issue has been happening for a year or two.

Thanks for any help.

 

Would a PCV Valve be a suspicion?

 

This forum sucks..

 

How do I delete my account??