Rough idling in parking and neutral

(DX model). I reticently cleaned my cars IAV and throttle body, the next day it started rough idling while it is in park and also in neutral. When I stop driving and it is in park it makes this churring sound like if it is loosing power, but the engine does not stall. It makes this weird sound like if it gains rpm's and then looses then in a steady rhythm. I did a tune up about four months ago so I know the spark plugs are good. I checked all cables they are firing just fine. I have yet to check the injector, I will update with a comment on that. What else could be causing this? Clogged fuel filter maybe? I doubt it though because in drive and reverse there is no problems. Oh also, when driving on the freeway it sounds like the engine is struggling to maintain its speed and the car shakes when I hit the gas and there is loss of power. Any suggestions?

Update: Well I checked the injectors there all firing just fine they could be clogged, but I am not sure; what I ended up checking was the cables cylinder three were not making good contact, the little metal part that shoots out the spark was way up in the plug so I pulled it down with pliers. I feel the engine has better acceleration speed on the freeway, but it still surges up/down in neutral and park. Please help. Thank you.
SP


Update: I ran the codes on my car. I got P0403 wich in my model car it is connected to the EGR valve, but as it turns out 1995 and below Honda's Model EX and DX do not have EGR valves. So I am stuck in a rut.