I'm new here btw, so I may not understand some slang around these forums. The car im troubleshooting is a 1998 honda civic ex coupe (d16y8) pretty much stock: i brought it almost 2 years ago. Straight to the point, a week or 2 ago I got a weird misfire on cylinder 4 After I fix some exhaust leaks. I change plugs about a year ago, change wires 3 months after the plugs and ran fine until now. I did more work before this like injectors and some coolant hoses and some suspension stuff work. Anyway I check the plugs, wires, compression (1: 116 | 2: 115 | 3: 120 | 4: 117) and check spark. All seem good, but I took apart the distributor just for peace in mind and saw corrosion on the cap, rotor and ignition coil. So I replaced all for those and still get a misfire on 4. I do hear some kind of spark noise from the distributor. I did check valves and no cracks or holes. I kinda lost at this point.

 

Sounds like you've covered quite a bit. Have you cleared the code, after the parts replacements, and it re-appears again on #4? If so, swap the #4 injector, with a different one, and test again.

 

I did clear after. It would run fine for awhile then slowly the misfire would come back. Ill try switching the injectors after i replace the distributor. The reason I'm changing the distributor, the pervious owner installed some Amazon junk called "mostplus" like the hell is that?

 

I'm using iridium spark plugs should I switch to original. I switched out my distributor and it seemed to be better (code for cylinder 4 is still coming back). I'm going to switch injectors as suggested. But I think I go back to original plugs

Edit: btw code for multiple multiple misfires went away.

 

I don't think there's any worry about iridium spark plugs. Sounds like the distro was a POS. Hoping swapping the injectors will get you an answer.

 

I swap injector from 4 to 1 and misfire moved. Can't believe i was panicking over a defective part. Ill be getting a warranty replacement today and pray this was truly the issue. Also I won't be returning the new distributor since I didn't trust the last one.