I recently had a problem with my 2002, Sonata, 4cyl, DOHC, Autotrans. Car would stall if I unless I held down on the gas and even with constant pressure the idle would rev up and down. I replaced the MAF which solved the problem. Car runs great now, but I have a check engine light and the code is P0171 system too lean. I reset the code by disconnecting the battery and it came back after 50 or so miles. I was told it make take awhile for the computer to adjust to the new MAF. Any ideas?