88 CRX DX is misfiring at low rpms, and bad gas milage. Replaced fuel filter ,and fresh gas. Recently replaced alternator. Car off. 12.53 volts, car running under load ac on, 14.6 volts. I ran tests on tps all good. new plugs wires, cap, rotor, plugs 6 months ago. Plugs look good. charging light now stays on all the time. Would this cause the misfiring?