https://www.greenhybrid.com/forums/f...-change-13135/

 

Thanks. I should have them early next week.

 

Did you inspect your current plugs? Mine were atrocious on HCH2 #2. Gap was 2X and horribly eroded.

Had NGK in front and Denso in back - both P/N listed in Honda manual. Not sure if they came that way.

 

I have not. I was going to check the front ones this weekend. I'll take some pics. That's odd that you had both brands in there.

Moving ahead, if the plugs don't fix the misfire where should I look next? Hoping it doesn't come to that but just thinking ahead.

 

it's possible that was done for a reason, like they didn't have 8 of one P/N in stock?

Both P/N are listed as valid in the Honda Parts book... or maybe a lazy person just swapped out the front, but they all looked liked ***** equally.

 

Got my spark plugs on Saturday. Going to put them in one morning this week.

 

The driver's side rear coil is hard to remove without pulling the cowl, and you have to be tricky with your extension choice when removing the rear plugs.

I use two of the short extensions, about 3" each. Socket and 1 extension lowered in, add the second extension, seat on the plug and use the ratchet.

If the cowl is removed, none of that is necessary. Anytime I see plastic clips or similar fasteners, I try to avoid removing it. I have a knack for breaking that stuff.

 

I've been reading a lot about clogged ERG valves on Honda-Tech.com causing random misfires. They state "Unplug your EGR valve's connector and go drive your car around. If the problem goes away, you have plugged EGR ports" I was thinking about checking this to see if mine was clogged.
http://honda-tech.com/honda-civic-20...2419426/page2/

 

If your plugs are original, they are definitely bad. Did you replace yet?

At your mileage, I would definitely check your EGR ports. When I replaced my plugs, all the misfires went away, but what I noticed then was what sounded like light detonation at cruise and/or gentle accel. 2 of my 4 EGR ports were clogged on the high mileage HCH2 and only slightly obstructed on the lower mileage one.

It's easy and pretty quick, but you'll want to use compressed air and eye protection

I've attached a picture of what mine looked like after the cleaning. I didn't have to remove the EGR valve, but I did to blow it out. I don't think it needed it. I did both cars at the same time since they were side-by-side.

After cleaning the "pinging/detonation" went away.

EDIT: You know, it just occurred to me that it was a combination of the two that likely caused all the misfire codes. I noticed that conservative driving is what initially triggered the codes for me. What made me suspect plugs is the fact that heavier accel caused the CEL to blink indicating active misfires, which contradicts what should happen if the only problem is plugged EGR ports. it wasn't until I changed the plugs, and all the codes went away that I noticed the pinging at steady-state and under light accel. THAT is definitely a condition caused by plugged EGR ports. In retrospect, it was probably both that contributed to the overall rain of misfire codes.

 

OK. Thanks for the info. I have my work cut out for me this weekend for sure. I will take some before and after pics of mine as well. Did you have an trouble with the gaskets? Also, do you think unplugging the ERG valve connector and testing it would hurt anything?