Recently the code po505 for idle control malfunction popped up. The car idles around 1k and then eventually drops to about 900. Then stays steady for a while. They randomly the idle will rise and then drop around 400 and then back up and fluciate for a little and then hold steady for a bit and then repeat. While driving whenever I lift off the accelerator the car hesitates and bucks till I get back on the gas again. When this happens I usually pull over and reset the code and then the car drives great for about 50 miles. However lately its been happening more frequently. I changed plugs , oil, air filter. I cleaned the iacv and tested to see if it would open ans close and it does. I dont know where to start because the idles isnt awful but the bucking is a pain. Also, sometimes I get a p1457 but not everytime. I'm guessing intermittent?

 

If the IACV gasket is dry and flattened that could be allowing a small amount of air in. Try replacing the gasket (includes screen). Remove and clean the throttle body thoroughly with throttle body cleaner and replace TB gasket with new OEM. Cann pull a used IACV from salvage yard and see if that solves the issue and if not return it for a refund.

For P1457 read this (reply #83): https://honda-tech.com/forums/honda-...3008037/page4/

 

I cleaned out the throttle body. Then went to a junkyard and found a IACv and a bought a gasket. And still getting the p0505. I noticed that the Rpms drop when I press the brake in and then go up when I release the pedal. I recently did a smoke test to check for a vacumm leak and found nothing. Not sure what to do next.