Heyo so short explanation: I've got a 1992 Civic DX with a b18b1 swap that returns a CEL around the redline(this model doesn't have a tach so that's just basic guestimation). I'm coming to here because I don't think there's a subreddit with a greater concentration of knowledgeable car people than r/projectcar. I'd just like to ask yall a few questions.

Its an educated guess because I don't have a tach, but I believe the powerband peaks before the redline, and with the CEL popping up around that area anyway, I'd like to lower the rev limit to be slightly underneath the red.

Will hitting the limiter and bouncing cause any meaningful damage if done occasionally, and never for more than a few seconds at a time?

I know handheld tuners are rather expensive, and I dont own a laptop, so is going to a shop likely going to be my cheapest/safest option?

On the check engine light itself, I'd like to attempt a fix just for the sake of engine health. I understand it could be a misfire and I should check the ignition coils, spark plugs and fuel system. But is there anything else I should consider, or a place I should start checking first for any of this?

I'd greatly appreciate any and all information from anyone with even a smidge of knowledge, and thank yall who do answer