hi i have a nissan navara 2.5 di .was diagnosed error code fuel pump.purchased 2nd hand pump with 3 month warranty and fitted , but now vehicle blows out tremendous amount of white smoke which it did not before . is this faulty replacement pump or could it be timing issues .may have to think about sending pump back to seller !.. i see on other forums people mention simple solution of filter replacement , could it be that simple ? also do these pumps have to be coded...thanks