Why is my 1998 Honda civic lx still overheating?

I've replaced the thermostat, water pump, timing belt, flushed the radiator and done a coolant test to check for gasses and all is good. The fan is wire up so it automatically comes on when ignition is turned on and is blowing the correct way. Do I need to try a new radiator cap or radiator? Engine light is on but it's for a 02 sensor. Any help is appreciated.

Head gasket has blown - have a look at coolant and see if little bubbles are coming up

Maybe your car is running on a lean air/fuel ratio, go get your car tuned on a dyno

If what you said is all done properly then you need to check your radiator. Is your car overheating during idle or when cruising. If it is overheating when cruising then you need to have your radiator replaced with a new one. The fins and passages inside your radiator could be blocked-up and no amount of flushing can remove that. When it is overheating at idle with a/c on then your condenser is at fault. With this one you can do flushing.