I have a 2001 Sonata with the 2.4 4 cyl, auto, it has been giving off an engine code of P 0171, running lean, Any ideas what needs to be replaced or repaired? The car idles very rough when first started and sometimes has a noticeable miss at around 35-40 mph
thanks

 

check the maf sensor (mass air flow) located in the fresh air intake tube between filter and trottle body -they have problem with them and will set lean mixture trouble codes

 

Your PVC hose from the valve cover to the intake is split.