I an having problems passing smog test in Calif. high rpm NOX. Blink codes indicate O2, bank 2. Both replaced but still same code. Testing indicates that VOLTAGE ON BANK 2 O2 is too low. Tested ECM confirms low volts, need 3ish and getting .87v. The real question is, if I by a 2nd hand ECM, do I need to program it or is 1995 too early to worry about that?