Noob here. Bought a used 2007 Honda Fit about a year ago and I really like the car. People are always amazed at the things I can (wait for it) fit inside!

About two and a half weeks ago I started experiencing an intermittent issue where the car hesitates/stumbles/hiccups/whatever you want to call it, usually in 5th gear, RPMs between 2300 and 2500, and while gently accelerating--but sometimes while at a constant speed. It has increased in frequency but still isn't happening consistently. After reading through the forums here it sounds like either a) spark plugs; b) coil packs, or c) all of the above. The CEL has never come on so I have been waiting for the problem to become consistent enough or the CEL to indicate a misfire in a particular cylinder to help determine the exact issue.

The second problem may or may not be related to the first problem. Yesterday, while sitting at a light, all of a sudden the "D" light started flashing, and at the same time the emergency brake and ABS lights turned on (solid). No noticeable changes in how the car was running. The stoplight turned green and I went through it as normal; again didn't notice anything unusual. The ABS and brake lights turned off after about a minute, but the D kept flashing. Again, no CEL. I pulled into an auto parts store that happened to be nearby and asked them to see if there were any codes, even though the CEL had not come on. They did not find any. When I started the car again, the D light was back to normal. I've only driven the car for about 10 miles since then, mostly on surface streets with a little bit of highway, and nothing out of the ordinary has happened since.

We have a trustworthy mechanic we've been going to for years, so I gave him a call today to see what he thought and whether we should bring it in since there was no CEL. He was concerned that the problems might be related and could indicate a serious transmission issue, which he said is common for Hondas. In fact, he actually said that if it were him he'd be looking at getting rid of the car before it gets worse and the CEL does come on. He's never done us wrong, but this seems a little extreme to me. I've done lots of Googling since yesterday but haven't found any clues that involve the same set of problems. Does anyone have any ideas regarding what could be going on?

 

Your car is in limp mode, the misfire has to get atrocious to set the CEL

Plugs,Coil-Packs,Valve adjust every 60 to 80K miles Just do it.. Its normal on these cars.

Everybody fights it...

Your battery could also be bad.. Mine raised hell when it got weak. Ran like crap.
if you get 3 years out of the little battery consider yourself blessed..

 

Thanks for your reply... I don't have a problem replacing the spark plugs and coil packs to start with, but it's not something we want to drop a few hundred dollars on if there's a larger transmission issue. Today it began shuddering while idling, though I only drove it a short ways and it only did it the second time I went out, not the first time. If it keeps up we might just get the plugs and coil packs changed anyway to see if it fixes the missing and cross our fingers that the other stuff was a one-off.

 

The shudder can be a indicator of tight exhaust valves. Mine was idling just a tic rough at idle before I did it. If the plugs are tired that would likely make it worse. You may also be due for a throttle body clean, they can get gummed up over time and the butterfly sticks to grunge on the wall of the tb..

 

Flashing D and abs/brake light on indicates intermittent problem in ABS unit (or input from one of the wheel ABS sensors).
Check for damaged wire!!
The code is stored in ABS and it is not a CEL code. ABS reader should pull it