Hondata

I recently tuned my 2018 honda civic sport (manual transmission) with the CARB +6psi calibration. Long story short I detuned the car because there were misfires showing up during gear shifts and sometimes while cruising in 3rd gear. I thought it was just a general civic thing but it does not misfire when flashed to stock, so I figured there's trouble with tip in on the base calibration. I know some people on here had a similar issue but it seems it was never addressed. I do have a Mishimoto intake, but it's for the stock calibration of the car and my trims are good with no misfires. I expected the basemap to be a little more robust considering no changes are allowed to be done to the CARB version. I don't feel any power loss, would be difficult to feel at a gear shift anyway, mainly the misfires that bother me. I'm on 91 octane and it's not bad gas.

Do you have a CARB FlashPro?

Indeed, I have the CARB FP, not the race one.

Have you changed the clutch or flywheel?

Is the intake CARB approved?

I have not changed the clutch or the flywheel and yes the intake is CARB approved. The trims seem identical tuned/ stock with the intake.

If the intake is what is causing the misfiring with a tuned calibration, then you might want to try without the intake and see if it Is any better. The FlashPro you have does not allow any tuning of the AFM for the aftermarket intake.

I will try cleaning the MAF and putting a slightly more restrictive filter on. I doubt I'll go through with installing the factory box though.

A more restrictive filter was a bad idea.. I think the factory airbox versus Mishimoto "stock equivalent" box work as intended.