2007 Accord Stumble
 

This is a 2.4 liter 5 speed with 183K. Developed a low rpm stumble/miss a few weeks ago. Ran some dry gas in a tank and some Techron FI cleaner in another tank with no improvement. Been running Top Tier gas from Shell and Exxon with no improvement. I checked my plugs and coil packs and all seem fine with no visual problems. I checked my PCV valve, air cleaner and cleaned my MAF sensor with no change. Last night I cleaned my throttle body which was not very dirty as I had done so about 25K ago. I then did the idle relearn procedure.

This morning on the way to work the stumble was noticeably worse, especially when shifting from 1st to 2nd and 2nd to 3rd. The rpm's seem to drop quickly and then when I get back on the throttle it will buck and jerk like a rodeo bull! Higher rpm's seem ok but feels like it may have less power. My gas mileage has been consistent throughout this ordeal. It seems to idle smoothly at around 800 rpm's but a few times when sitting in traffic this morning it almost stalled when the cooling fans came on. It also threw a check engine light this morning so I stopped at Advance Auto on the way home but they no longer will scan codes.......told me it is a "liability"? I guess I need to get an inexpensive code reader. Any suggestions on a code reader or what else I need to try to diagnose this problem? thanks.

Sounds like an IAC problem, but you need to get the code(s) before anymore troubleshooting can be done.

It is my understanding the 07 does not have an IACV. Can someone confirm?

Ah...you're correct, this is a drive by wire throttle body. No IAC.
Still need codes.

Got any other car-parts stores that might read the codes? AutoZone? OReiley's? Pep-Boys? Worth a couple phone calls to find out.

What did you do for the "idle re-learn"? I thought the cars with motorized throttles have something completely different that uses a Honda programmer tool hooked up.

Disconnected the battery for 10 minutes. Turned key on for 2 seconds. Started car and ran at 3000 rpm's until cooling fans kicked on for one cycle. Left idle for 5 minutes not including any time the cooling fans ran.

I am embarrassed to say that upon further inspection of the air duct that runs from the air cleaner to the throttle body I found a large vacuum type unit was unplugged on the backside of the duct! Must have pulled out when I unhooked the duct to clean the throttle body. Runs a whole lot better! Ordered my own code scanner off Amazon tonight as well. Feel kinda stupid but glad I found it while looking for holes in the duct. thanks for all your help.

I think that beginning in 2003 the cars used non-volatile memory. So disconnecting the battery will not clear any memory.

Thanks, maybe the new scanner I ordered will clear it for me. I will have to check it out when it arrives.