To take what jymmie said even further. If you repair the reason you have a lean fault and then just clear fault codes. The light will come back on right away.
Good example: someone forgets to push the dipstick all the way in after filling with oil. It's a throwback from working on the old pushrod engines I suppose. The way they just wont take oil at large volume if the dipstick isn't out of the tube to let air rush out the tube when the oil goes in. Well if the tube is left up on those engines the light will come on when you test drive it for lean faults. At that point you have to reset adaptions to get the light to stay off.
Also would add that you more than likely have restricted injectors causing your lean faults. The cheap fix is add 44K to the fuel tank for the next couple fills. The fast fix is flush the shit out of them. I sometimes do it several times and retest the fuel trim adaptions each time. You can watch the fuel trim come closer into spec between each flushing. The best fuel injector cleaner I've used is a General Motors product called Top Engine Cleaner. You can buy the stuff in little 2 or 4 oz bottles and mix it with a canister of gas in a fuel injector cleaner canister.
Good example: someone forgets to push the dipstick all the way in after filling with oil. It's a throwback from working on the old pushrod engines I suppose. The way they just wont take oil at large volume if the dipstick isn't out of the tube to let air rush out the tube when the oil goes in. Well if the tube is left up on those engines the light will come on when you test drive it for lean faults. At that point you have to reset adaptions to get the light to stay off.
Also would add that you more than likely have restricted injectors causing your lean faults. The cheap fix is add 44K to the fuel tank for the next couple fills. The fast fix is flush the shit out of them. I sometimes do it several times and retest the fuel trim adaptions each time. You can watch the fuel trim come closer into spec between each flushing. The best fuel injector cleaner I've used is a General Motors product called Top Engine Cleaner. You can buy the stuff in little 2 or 4 oz bottles and mix it with a canister of gas in a fuel injector cleaner canister.