wild thought, u sure all your plugs are connected entirely on the distributor? ive had encounters where they seemed as if they were in but when u give then an extra push they'd click in further. just a thought, sometimes its the little things.
Im pretty sure honda fuel filters are around 12 bucks. As for cleaning injectors, put some fuel injector cleaner into ur gas tank. to check if an injector isnt firing, get a stethoscope and listen to each injector individually, working ones make a tick each time everytime.