My 2007 Fit with 190 k miles misses at idle. There is no check engine light. I don't think it is a coil pack, as it runs just fine under load during acceleration, normal running and at engine speeds above 1200 RPM (in neutral sitting still). I have run a bottle of Techron in two tanks of gas. Both times it cleared up with the Techron treated fuel. The problem then returns when I go back to straight fuel. My guess is that there is a sticking injector causing a misfire on one of the cylinders. Any ideas before I change out the injectors? Has anyone else experienced this?

 

It's either beginning of coil failure and or valve adjustment. If I recall my early coil replacement symptoms were idle misses at red lights, then later it started getting misses on highway. Valve adjustment fixed my rough idle on cold startups.

Try these $6 coil replacements https://www.autozone.com/ignition-tu...58986/193447_0
If you have shoprunner it'll give you free shipping.

 

I would start with a valve adjustment. They usually need it by 100k

 

Thanks, It doesn't miss when cold, only after it has warmed up a bit. I will try adjusting the valves as that is cheap and probably needs it anyway. First law of mechanics, "start with the simple things first".

 

Check your coil packs, my CEL didn’t read anything until I was only using 3 cylinders while driving