Hondata

Hello ladies & gents i need advice
Having random issues with my 2009 civic si coupe.
FBO + rdx injectors, stock TB/IM,
Tuned here with my dyno tune and etune Merge.

Car has begun running strange for 1 week. Since misfire in cylinder 4 (engine light flashing, fluttering, limp-ish mode) we have swapped ignition coil cylinders 3 to 4 and sparkplug 3 to 4 to see if 3 misfires, it does not. cylinder 4 error still pops up.
Car drives a bit choppy, flutters here and there with engine light sometime flashing, most of time it does not
I included 2 datalogs one is with error code misfire cylinder 4
The other log everything is the same but no code pops up.
I can do better log WOT 2nd and 3rd just let me know, these are random driving, traffic etc.

Notes: recently installed new AC compressor and condenser and oem new belt. Previously i had NO A/C compressor and was using a shorter belt that i was tuned with.
Will really help if datalog shows any helpful info will help me save time with my process of elimination.
Pls & thanks. Good day

Have you checked the spark plugs?

Hello yes. They look like they shouldn't be causing problems, normal I think. Its been almost 2 years 20k kms. I will get new ones now and check if it helps.
Photo attached, all look very similar

Hello. new plugs in, laser iridium again.
definitely feels better, thanks for recommendation. (less than 2 years >20k kms on those old plugs im confused with the life on them)
Anyway attached is a datalog a couple of WOT, when you have the time if you can tell me if everything looks good. or i can post it on the calibration section.
Thanks goodday

At times you are running extremely rich. eg 7:18, 10:45 Not always at WOT.

Not sure if you are using mass flow or VE tuning, but it is rich enough to misfire I would think.

Hello can I attach my calibration here to look at? I am not sure. I can do so once I'm infront of my laptop.
Thanks

Hello, im not sure what ive changed on the car for it to become extremely rich, ive replaced the 6.5 inch hybrid racing filter with new one, A/c compressor was added, RPF1 wheels and tires added, AH & i swapped my raspy cheap rev 9 muffler to a vibrant street power oval muffler same sizing
(?) attached is my Calibration, Can you let me know what i should do to eliminate the extreme richness. thanks again! good day

OK i see what was happening at 7:18! it has happened hand full of time when id be in vtec then upshift or downshift and it would flutter like it doesnt know if it should stay in vtec or not. Notes:my explanations are not the best. thanks

Hello an update. went thru a bunch of things with my mechanic. We found a small exhaust leak at the flange so we replaced the gasket. Could this have caused extreme richness at part throttle or could it be some type of bug somewhere?

attached is a new datalog today of WOTs and me trying to replicate the part throttle richness.
any support is appreciated, would love to pinpoint the issues before any track day or drag strip fun.
Thank you

It looks better

Spunkster wrote: Fri Jul 14, 2023 9:24 am It looks better

Ok thanks

Hello update.
Car is still being funny again. It's misfiring 1 exact time, it's when upshifting while in vtec and part throttle.
I replicated the misfire many times this weekend.
Absolutely no idea what to try next.

Maybe it's wear and tear and the summer heat, so i tried to asked my tuner Kyle from EFI for tweeking, but there has been no activity on here or elsewhere sadly.
Should I ask Ed from calibrations for a new tune/retune and go from there?
Or any other recommendations to check or replace parts?
Thanks.

You will need to post the current calibration and a datalog showing the exact issue you are having now.

Hello i believe its at cursor 3:12, total log length 15:07.
I also gave more throttle at 3:34 then upshift, this seems more clean while giving more throttle..
this may sound confusing but this is what i notice while driving

I don 't see anything that is standing out to me.