i have a 98 accord lx sedan, its in really good condition, about 90k miles, but lately its been idleing pretty ruff, more with the ac on, the rpms idle below one but if i slowly hit the gas in park, it completely stops the "ruff" noise, but then when i let my foot off the gas, it comes right back, it can be really annoying if you're trying to get warm or cool off and are just sitting in the car, whats wrong?! lol thanks!

 

get an engine oil flush and rad flush.