well that didnt work.

 

i just read a little from my haynes manual, and it mentioned a vaccume leak could be the problem... but i dont remember seeing a vaccume hose anywhere... i had to remove the entire air filter assembly (including the big plastic part to the left of the engine, not just the part where the air filter goes), so did i miss something????
ill take it all apart again tommorow and see is i see anything.

 

i replaced my Air Idle Control valve with a new one. it "maybe" has a tad more acceleration, but basicly, it didnt help either. still bogging down pretty bad comming off the line.
ive now spent close to $500 replacing various things, and it still hasnt helped. what else could it possibly be???!!

 

Maybe you should just go to a Honda dealership and have them check it out that way you don't keep throwing money away on guesses

 

Take It To a Shop all The money spent you could have had a shop tell you. hope u get your car right

 

i took it to the honda dealer a few weeks ago, and their recomendation was to change the Ait Idle Control Valve. but they wanted to charge me twice what i paid for it, plus labor, for a whopping $1000. i changed it myself for much much less, and it still didnt help. plus, they told me at the time, this may not fix it. -so they were guessing as well. the only other option was to swap out the ECU (computer "brain"?).
they are guessing also, and would cost me a fortune. this is exactly why i do all my own car repairs. mechanics dont KNOW either, but they cost alot.

 

Computers cost about 300

 

Do you have cruise control?
I have a similar problem with very low idle and misfiring P1399 P0304 P0302 P0300. CEL light flashing at idle. Car has new wires, plugs, rotor, distributer cap and cap seal. All from the Honda dealer No oil consumption no coolant consumption. Swapped injectors Cleaned IACV 2 times. Changed intake manifold gasket. Seafoam treatment. Today started checking vacuum leaks.
disconnected cruise control vacuum line and idle increased by 200 RPM. Test cruise control system by driving car and using system, it works. Trace vacuum line back to Cruise control actuator assembly. disconnected and test drove the car The result was CEL stopped flashing during idle. I cleaned the Idle has increased and car running much smoother. This is something you can try without spending. There is a vacuum solenoid valve system inside the actuator that I cleaned the filter cover seal. This resolved the misfire and flashing CEL at idle for me. Worth a try if you have cruise control.
Best of luck

 

thats a great idea and ill look into it for sure!
i wanted to add here, that i recently took it in for an oil change and had them do an injector cleaner service on it. lots of white smoke came out from the tailpipe. it ran smoother for sure, but still "puttered" at idle. a friend suggested that i buy a bottle of octane boost and a bottle of injector cleaner and out them both in. that cleared everything and it ran great! i did it twice, and the 2nd time i bought the stuff, they guy at autozone said its the bad gas these days with all the ethanol. -im not so sure about that because it ran fine even after they boosted to 10% ethanol... but im trying 93 octane right now, and the "puttering" is back. slow and hesitant off the line. so its not a "bad gas" issue either. and at $5 a bottle for octane boost, its an expensive "solution" to a different problem.
FYI

im going to look into cleaning the cruise control vaccume lines and solenoid, ect... cant hurt, and its free.

 

The IACV has nothing to do with acceleration or running bad on the highway. It's only for idling.

If it idles badly disconnect fuel injectors one at a time and see if the problem is based on one cylinder. If you're running on 3 good cylinders it will be reasonably smooth. If there's a bad one in the mix it will be worse. Another thing to do is remove the spark plugs and inspect if they are the same color. If one has a different color, something is different about that one cylinder.

Fuel injectors can be removed from the car and cleaned with spray cleaner. That is a lot more certain and direct than waiting for magic in a can added to the tank to happen.

Have you checked the cam timing? Timing belt having skipped a tooth will make the cam out of time and hurt performance. Also valves adjusted too tight will cause loss of compression and misfiring especially at idle.

After looking at mechanical factors, it could also be:
Fuel pressure / flow issue, check with gauge.
CPS sensor as others have mentioned this times the whole operation of the engine. "Misfire" codes are set because the ECU sees fluctuating readings from the CPS, which could mean the rpm dropped abruptly because a cylinder misfired-- or it could mean the CPS skipped a beat itself -- which will cause a misfire -- classic chicken or egg syndrome.
MAF sensor also a vital input to get the fuel mixture right-- any air leaks after the MAF will cause its reading to not represent the actual airflow into the engine thus it will run lean.

Cruise control just disconnect the line to the manifold and plug it so air can't go into the manifold, test drive like that all should be fine except you will have no cruise of course. You could also pinch off the line to the brake booster while idling to see if there's a leak in the booster.