1997 Ford Taurus car smells like gas

I have a 97 ford taurus gl 3.0 and i recently had to replace a maf sensor ( when i replaced it, the old one had a pool of gas/oil mixture. ) and a fuel filter. which btw the gas smell originated before replacing them. and after doing that i searched for a gas leak, and checked o rings which are fine. the gas smell comes from both inside and outside the car, when inside the car the smell seems to come from the front engine area but when outside parked the smell comes from the back near the gas tank (smell is strongest on rear right side near the rear tire) and i cannot fine what is wrong. i know i replaced the fuel filter and maf sensor correctly but still no change in smell.. im open to all suggestion, thanks in advance. Ryan