My dad has run many labor Clubs now and had people coming in trying to sell magnets for the beer line, as the magnetic force re-aligns the electrons of the beer, so it does not stick to the lines so you don’t need to clean them as often "YEH RIGHT", the last club he took over had these magnets installed, surprise surprise they made no difference, They are marketed diffrentley, but they dont make fuel burn better either
ecu-reset, this will reset the catalyst monitoring data and Long and Short Fuel Trim, fuel trim is the adaptation of the ecm for varying sensors and engine efficacy, when the car goes in to closed loop at a given state (load, throttle position, rpm, coolant temp .etc) it expects what the opening time of the injector will be as is changes state, from rich to lean or lean to rich (closed loop) . If the actual opening time is more or less the ecm will add or subtract fuel trim (it learns). what this does is make the car run closer to the correct AFR, if the ecm needs to trim to much it will log a fault and bring on a light . Eg. Bank 1 system too lean. The car will learn very quickly if anything changes.