Do you have any way of checking the code it's throwing? Swing down to autozone or something, they can probably hook it up and tell you. Or spend under 100 bucks and invest in your own diagnostic tool. When the light initially came on, what prompted you to replace the EGR valve, clean the TB, and so forth? Or was it the EGR replacement that started the light coming on? Bottom line is if you have the light on, figure out what codes are being thrown, and then we can help you fix whatever the actual problem is. The amount of time/money/aggravation you'll save by taking out the guesswork is well worth it. Most people (myself included) top off a lil after the automatic shutoff on the pump. If you overfill, you'll know it just because there will be gas running down the side of your car