1997 Mercury Sable Q&A
1997 Mercury Sable Question: P0411 and error code,can't locate diverter valves to check them.
p0411 is for secondary air pump. air pump located between radiator and transmission. diverter valve located under intake tube between air filter and throttle body. p0420 is for catalytic converter bank 1 which is the rear converter. - mrfordman