Ihave a 1993 Civic Ex Coupe and one day when i was driving it started Idling low and bogging out. ITS NOT THE o2 SENSOR!!!. like when i am sitting at a light it drops to almost 0 and then jumps back up. It usually only does it when its warm..so i changed the fuel filter and cleaned the air filter...what else could it be?

 

Anybody?

 

does the idle go up and down all the time when you come to a stop. i think i had a friend that had the same problem. I think he got rid of the car but i think he knows whats wrong. i'll leave him a message and i'll get back with ya as soon as he answers me.

 

O.K. its good form to wait 24 hours for a reply before bumping. That said lets see what we can figure out.

How do you know its not the 02 sensor?
Have you checked for vacuum leaks?
Are you sure that your timing and idle speed are set correctly?

 

Not o2 sensor because just got a new one..and it only goes back up when its about to stall..

 

Still don't know this problem... Anybody?

 

pcv valve perhaps? what kind of modifications have you done to your car?

 

Aem SRI, Headers, exhaust andjust today a chipped ecu. Where the PCV valve? ive looked but couldn't find it

 

it's different on dif models on some it's on the top of the valve cover, at the end of the vac line leading to the intake manifold some models it's harder to get to. Follow the vac line. But I bet the chipped ecu has something to do with it.

 

No i installed it today and its been like that for a month