If it is still under warranty, then definitely take it to a dealership.

 

Regarding the missing. I had my 03 MDX suddenly start random misfire at about 90K miles. I pulled spark plugs and found Bosch plugs. Someone had removed the OEM plugs and substituted Bosch. I installed new plugs and restored smooth running.

That's why I suggest starting w/ plug removal and inspection. You may find aftermarket plugs.

good luck

 

Thanks for the help guys, really appreciate it. I found out the source to the misfiring, cylinder 4 coil is the problem. The plugs are oem ngk but looks like they need to be replaced. Is it possible cylinder 4 coil was damaged due to the constant revving that occurred? Either way I'm going to replace it asap.

Texas, you mentioned that the accord doesn't have a FITV but something similar, is it a part that can be cleaned? Also, the IACV is the part that has black plastic plate looking thing with some special rivet like screws correct? If so how do I remove it?

 

I doubt that the coil went out due to revving. I would start by replacing the coil and the plugs. See if that repairs the revving problem.

If the idle problem returns, then you should diagnose.

You just don't want to do two repairs at once, because that could complicate diagnosing the problem.

 

Good advice from PA. Don't create a problem by removing and cleaning something that may be OK. Wait and see what replacing the COP does. Strange to get a random misfire w/ Cylinder 4 faulty COP. Any chance you had a P0304 also?

good luck

 

Just one code, P0300. I'll change the coil and the spark plugs and see if it fixes the problem.

 

Update, I changed the 4 spark plugs and cylinder 4 coil. It seems to be working ok, the cel went away and and i added 70k+ miles test driving it and the car hasn't had an idling problem as of yet. I'm going to do an oil change this weekend and probably flush the radiator as well. Thanks for the help guys.

 

Thanks for the update. Hopefully the problem is solved.

 

Hello everyone, I have a similar problem as 07AccordCP. My 2005 Accord 4 cycl EX, 74,xxx miles idles high (around 3,000 RPM) on hot days with the AC on. When I'm in parked it won't let me shift to drive obviously because of the high RPM's. Turning the AC off doesn't help much. Turning it off and waiting 15 minutes or so doesn't either. The only way to lower the RPM is to physically poke the throttle body lever down with a screw driver, but after a few minutes it does it again. The next day everything is fine with the exception that it feel a little sluggish. I sprayed and cleaned the throttle body, the MASS air flow sensor and oiled the links a few weeks ago. I'd be grateful for any advise.

 

If you can poke the TB and it drops OK, then I suspect something mechanically binding the throttle plate so it doesn't close all the way. Excess friction at the throttle pivot shaft? Excess friction in the throttle cable? Stuff like that...