I have a 1998 galant es 2.4 4cy. I have 154000 miles on it and I have two questions. What all do i need to check and replace on my routine maintenance to keep it running another 150,000. also I have a code po100,and po1400. stating my maf, and map need changing/ i changed them out cleared the codes stayed off. next time i drove it the light came back on. I have cleaned the throttle body up still reading codes. please help???? what could it be? could it be an o2, vacuum leak, egr, what??? I need help.