So my '07 Sport (101K) threw its first code since I've owned it (less than a year). I have no complaints whatsoever with the mechanical operation of the car up to this point. After purchase I did some basic tune ups which included new plugs at 90K. Since those new plugs, everything has been great (hello 39MPG on highway runs).

The car sat for a week at the airport, drove home from the airport with a little lagging during acceleration, but no code (thought it might be the clutch going). Then today, it was noticeably worse and started throwing the P0302 code.

I know misfire codes don't always mean a true "misfire" (from what I've learned it's a crank rotational speed issue, usually caused by misfires), but from the research I've done for the Fit, it seems that most folks have replaced the coil on the trouble cylinder and that did the trick.

TLDR: cylinder 2 misfire code. Is purchasing a new coil the best first place to start in tracking down the issue?

Thanks!

 

You already replaced plugs...hopefully with the proper Iridium type.

So, your next steps are to:

1: Adjust Valve Clearances

2: Replace ALL the coil-packs (OEM or Hitachi part # ending in 053). Hitachis will cost ~ $200 from Rock Auto or similar. When one fails, the others are not far behind...

 

Thanks for this, CarBuff.

Plugs were replaced with NGK IZFR6K-13 Laser Iridiums.

I'm not flush at the moment, so only ordered 1 Hitachi coil.

Question... would you replace the plug as well?

 

Re-set the code and swap coils.
See if code follows the coil.
typically coils ##4 and 3 are failing first due to higher temperatures at this area.
Also, check the plug #2 cylinder for tightness. If plug worked itself loose, the combustion gases will burn the coil
Be advised that when you removed and reinstalled original plug for whatever reason, the micro pits on plug gasket surface will allow some very minor exhaust leak into the spark plug well

 

I'd inspect the new plug but not replace.

Yeah, make SURE the plugs are all tight, had one loosen on us 10 months after replacement. I could hear the 'puh-puh-puh' at a cold start.

I'd swap coils as suggested by doctor J. Also, DO THE VALVE ADJUSTMENT. If you DIY, you are spending time, not dollars. And I'm sure it will be worth the investment.

 

Yes, this is the step in troubleshooting I knew I was missing.

Thanks!

 

Thanks for the emphasis on the valve adjustment... It's something I've not yet done in all of my wrenching, but I'll look up the process and see what all is involved.

 

You may find the coil easily. On our Fit, one cylinder has weak spark plug threads and that plug loosens over time. It eventually deposited enough soot on that one coil to make it fail. One new Hitachi coil and all is good again.

If one coil is sooted and the others are clean, it's most likely the culprit.

 

Thanks for the tip!

 

Little update...

I swapped coil #2 with #1 and took it for a spin and sure enough, the code jumped along with the coil, spitting back a P0301.

While I had the coils off, I pulled both plugs as well and everything looked alright / no difference between the plugs. Nor were there any deposits on the coil boot.

The new Hitachi coil should be here tomorrow. Will update when it's swapped out and hopefully running well.

Thanks for all your input.

 

So... that was nearly 4 years ago and here I am again with a P0302 code and a definite misfire. The car is running terribly. Oddly, I've also got a 61-1 ABS system Control Unit Low Voltage code which I believe means low voltage during cranking which could mean my battery is on the way out. If the battery is on the way out, could that affect cylinder #2's coil?

Sadly, I never got around to the valve adjustment in 2017 nor since. My fault, and maybe the cause of the current #2 misfire.

I'm going to run through the steps again that I did in 2017, but considering everything is still fairly new, I'd like to see what folks think could have caused this to happen again so soon?

Last occurrence was October of 2017 with 103,xxx on the odometer in Virginia. Fixed via new plugs [iridium] + coils [Hitachi IGC0053].

Current occurrence - June 2021 with 155580 miles on the odometer in Los Angeles.

Will be tearing into the car later today and tomorrow.

Thoughts?

Thanks!

 

For whatever reason, valves out of adjustment and/or old spark plugs seem to cause coil failures. We are at just under 200k miles on the original coils while many seem to buy a set every year. However, the car has also had 4 valve adjustments with spark plug changes in it's life.

 

Automobiles are a SYSTEM these days...a lot of coinciding factors can affect running.


I'd start with a valve adjustment, for sure. Our '07's definitely needed adjustment each time we checked them (3 times in 152K miles).

Spark plugs with eroded gaps (too much clearance) can overwork the coils since it takes more energy to spark across a wide gap. (That is why some folks here run narrower gaps, only 0.35") Since it is easier to turn the engine with the plugs out, you would look at them anyway in the course of the valve clearance check.

Don't forget the another common issue: Loose spark plugs.

 

Thanks to you both!

 

make sure the spark plug is not leaking. This weekend on the PYP in Anaheim I saw the car with replaced coils.
The plug in cylinder 3 has been leaking badly.

 

Thanks Doctor J.

I'll be sure to keep an eye out for that.

 

"Leaking" = loose plug, right? The blowby gases turn the sides of the coil brown.

In our case, I noticed the Poo-Poo-Poo sound at cold startup, but it went away when the engine warmed a bit.

 

Some plugs were tight (cannot torque anymore with reasonable force) but leaking (maybe someone just tightened them again)
On few other cars (2002 Accord, 4 cylinder and 1987 Camry), the plugs (same diameter and gasket type) were only finger tightened (not flattened gasket) but did not leak.

 

Had a chance to pull the packs and plugs today. Here is what I found. Easier to view photos here: https://drive.google.com/drive/folde...4W?usp=sharing

I've NEVER seen this (the loss of the center electrode) happen to plugs in any of my vehicles before. I'm obviously VERY curious to know what is happening especially since the car has been running really well until the 0302 codes and misfires: No drop in fuel economy, no performance loss, etc.

All plugs were not very tight, but plug #2 was very loose and lug #3 was noticeably loose as well.

These plugs (and coil packs) have 64,824 miles on them.

Plugs: NGK IZFR6K-13 Laser Iridium Spark Plugs
Coils: Hitachi IGC0053

Should I also replace the coils along with the plugs?

Please share your thoughts.

Thanks.

 

UPDATE...

Did some receipt digging and realized I bought these NGK plugs from eBay. Counterfeit plugs are (apparently) notoriously common and that HAS to be what happened here.

Going to order new plugs from Rock Auto and see how we go.