I have a 98 civic ex... I replaced the IACV, TPS, fuel filter, distributer cap/rotor, thermostat, battery cable ends and spark plug wires.... When i start the car it starts fine idles at about 1,000 rpms but after the motor warms up the rpms fluctuate between 1,500-1,600... What could this be?

 

Post all CEL codes that are thrown.

Is the hunting idle a long term or recent problem? Give some background.

Did you bleed the cooling system properly?

 

The only CEL code i got was p0505

This started about 1 month ago i figured it just needed a tune up, so i gave it a tune up minus the spark plugs... So then i put the TPS on it and then the check engine light came on, i pulled the code got P0505 replaced the IACV and the light came on again with the same code.. So to answer your question it's been acting like that for about a month now

And no i didnt even bleed it because i'm getting new radiator hoses and clamps