well for the past month, my check engine light has been going on and off. after doing a free diagonstic at Advance, i got the p0410 code. To people who have already been in this position: is the pump the only thing that can be malfunctioning? Must it be replaced? If so, how much did you pay? I'm going to try this corrosion cleaning b/c mine looks like this pic. Is it bad for me to be driving while i'm in this situation? the car is driving normally.