When it rains, it pours....I just installed a new rear 02 sensor, thinking that it would remove the CEL - wrong! I know the old sensor was bad because it fell out and was dragged for about 1/4 mile down a highway. Anyway, after installing the new sensor, the CEL remained on. I checked and am a 7 and 8 flash code, one of which could mean the evaporative cannister. Would a bad purge valve make the car hard to start when warm? I notice that I have to spin the starter for about 5-10 seconds before it'll catch, where normally it fires up almost instantaneously. Also, the fuel gauge has been acting funny, lately - it reads almost empty when I first start the vehicle, but will slowly rise to the true level, after about 5 minutes. Also, I notice quite a bit of pressure difference when I unscrew the gas cap - haven't determined whether it's air rushing in, or vapors rushing out. Finally, my water pump: this engine has about 50k miles on it and I noticed a slight leak coming from the bottom of the water pump. I thought it might have been a loose 12 mm bolt on the cover, but upon tightening it down, it's still leaking from what looks like the gasket that is under that front cover. The water pump is not leaking from the seal on the main shaft, and appears to provide a healthy flow rate of fluid. Is it possible to replace that gasket or does this mean I'll have to get a whole new water pump?