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?

 

Make sure there are no air leaks in the intake tube between the MAF and the Throttle body.