now that its getting cold here in florida in the low 60s in the morning compaired to high 80s and 90s, iv noticed my car runs sooooo much better. it idles smoother, it rev's more smoothly, has much better throttle response the whole spew.

ya iv herd the whole whole cold air is dense but i dont think that would mach much of any difference for a bone stock 98 civic.

anyone got any ideas on whats going on when its realy hot outside to make it change?? coolant temps are fine. i was thinking maby my air filter is getting clogged less cold air is better than some hot air idk.

 

Just a thought..........what about the summer/winter blends of fuel? Could be your Honda likes the winter blend of fuel better!

 

i would look at iat sensor resistance could be going haywire when warm, same as for coolant temp sensor.

but if it were me i would be looking at main sensors that control fuel/ign mapping. iat, map, coolant temp, map, things along those lines