i've been having problems with my accord recently and i plugged an OBD into it and i got a bunch of codes. every cylinder has a misfire, O2 sensor bank 2 sensor 1 no circut activity, relay control module lost communication with gauge control module. i have no clue what could be causing the misfires because i got brand new sprak plugs and coil packs last year. i think it might be fuel related because i always drive around with a quarter tank of gas

 

could be your injectors try using a injector cleaner like Seafoam. the constant misfires could have ruined your catalytic converter.

 

How would i put it in. Does it just go in the gas tank?

 

Add a can to a full tank.

 

read the directions on the bottle.