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.