Hey all,

New member here of low skill level so apologies if this has been covered somewhere else. I know Honda idle issues get brought up a lot here but my misfiring actually occurs worse when accelerating

I have a 2007 base model Honda Fit (automatic) and I'm trying to determine the source of my engine misfire issues. As I mentioned it does in idle but particularly when accelerating at higher expressway speeds. The CEL comes on periodically and the problem comes and goes but seems to intensify/cue the CEL when it's warm out (I'm up in Toronto) or when I've been driving for longer periods. This seems to indicate to me the problem is connected to the engine heating up and thus it may be the IAT not functioning properly. But I'm no expert so that's just my guess from the research I've done.

After a code reading all four cylinder misfire codes (P0301-04) come up as well as the random misfire code (P0300).

It also spit out a high pressure on the IAT (P0113)

and one for the MAP sensor (P0108)

I've checked the EGR valve (as I've seen many say that's rarely the issue and of course it wasn't clogged), I can't get at the passages myself because of the angle, I changed all four spark plugs with new NGK iridium and tested the coil packs. All four give good readings (exactly 1.8 across the board from the ohm meter), which seems to me to indicate that it is indeed MAP or the IAT that is the source of all the other problems/misfire codes.

I'm looking for advice on whether the MAP or the IAT would be the original source of the issue. It's of course possible both are faulty but I just wanted to hear some thoughts so I don't buy a replacement for the wrong one and end up having wasted the money.

Is one typically the source of issues with the other? Or is this combination of misfire codes indicative of something else entirely?

Thanks!

-Adam

 

I have the same problem with my 07 SE fit. I just had all 4 spark plugs replaced by the Honda dealer, but my engine is still misfiring. The dealer recommended I change all 4 coils but that would be $600+ so I said no I'll wait on that. The thing is my engine light is not on. I have had an ignition coil replaced recently and it seems to have started after that.

Any suggestions would be greatly appreciatet, thanks guys!

 

Hi everyone. New user but I had to sign up after I saw this problem. I just got the exact same codes (P0113, P0108, P0300-P0304) in my 2008 Honda Fit Sport this morning. I recently replaced the spark plugs after I noticed some vibration/hesitation at stop lights. That solved the problem for about a week and a half and then the vibration returned. I haven't replaced the coil packs yet but I don't want to throw more money away without some hope that it will fix the problem. Any help would be greatly appreciated.

 

The typical causes of misfires:

1. Spark plugs (replace with Denso or NGK Iridium only)
2. Coils (use OEM or Hitachi part # ending in 053). If one fails the others are not far behind.
3. Valve adjustment

If replacing / adjusting the above doesn't eliminate the problem, post back.

NOTE: PLEASE use the parts noted. Cheaper alternatives only work temporarily.

 

Thanks for the reply and the information. The first two codes I received were for the temp sensor and the MAP sensor. Could these have been thrown based on a bad coil pack(s)?

 

^^^ Those codes are a whole different kettle 'o fish.

I've gotten those codes when I removed the intake to clean the throttle body and forgot to connect the wires. D'oh



You don't run a K&N or other 'oiled' air filter do you? The oil can foul these sensors.

I'd resolve the misfires by verifying the above three things, clear the codes, and see what comes back (if anything).

 

Rock auto.. Rock Auto.. Rock Auto...

Denso sensors are usually fine. When you tested the coils you were testing the einding, that doesnt mean the rest of the assembly is good.

and +1 on the plugs/coils/valve adjust.

 

is it possible to set a misfire without setting off the CEL? To this day driving a 5spd i haven't noticed it yet.

 

Yes, you can have misfires and the CEL will not illuminate.

It takes repeated misfires to turn on the light. But you could 'feel' them in the operation of the car.

 

I got those codes when my battery was dying.. On both the fit and when the battery died on my BMW. Worth checking..

Only the MAF sensor (Which GD3 engines don't have) is typically a problem with oil fowling.
The IAT is a simple plastic covered metal peg and the MAP is a metal diaphragm that is down a fair bit of tube from the intake.

MAF cleaner is a good way to clean any EFI system which kinda needs done annually for most rigs far as I can tell.