idle surge

well im goin crazy with this damn civic its a problem child... i am about to give it a tune. I was havin problems wit the idle... surging way up ten way down about three weeks ago i changed the idle speed control valve and everything was ok. now the car is trippin again doin the same thing with the idle. a buddy from work told me togo ahead with the tune up and change pcv and o2 sensor what do u guys think it may be. is there anything else i can look at or change to solve this.....

Is it bouncing exactly like it was before on the rpm scale, or different? did you make sure the hoses on the idle air control valve were free from clogs and leaks? did you check for vacuum leaks? Hows the TPS? O2 sensors malfunctioning will show up very quickly on the CEL (trying to save you some money. PCV valve may solve the problem, but, very unlikely element. other causes for your erractic ldling could be from a leaking EGR valve, your air filter is clogged, fuel pump not delivering enough fuel, timming belt or pulleys worn, your camshaft lobes are worn, leaking head gasket. Mileage on the car? what is the engine model?

take fast idle valve off intake and open it and clean really good put back on should solve your problem .. it should be just like an accord motor with that same problem i just fixed mine like a week ago...

its most likely your TPS right on the Throttle body, same prob with my teg, and a friend of mines civic just goto the junkyard and try to get the Throttle body, it comes with the sensor on it, noone sells the sensor separate, that will fix the prob.