I have a 1999 ranger 2.5L engine. I have downloaded code ( P1401 manufacturer controlled auxiliary emission controls ) ( PO300 random multiple cylinder misfire ) ( PO 171 system to lean bank one ) witch is really strange because it is an inline 4 cylinder. I have changed both coils and the delta pressure sensor for the egr valve. I have also checked the maf sensor and it is good. Any ideas on what to do next.