Hello, I have 99 TL and I noticed one evening when standing by the car a humming noise from the car! It stopped and about 5 minutes it started again and so on. Well I went to searching and looking in car and underneath car and I could hear it better underneath and it sounded like a darn fuel pump coming on and off? Is this supposed to happen??? I've never heard of it,I've been around cars most my life and don't think so. Anyone heard of this happening with the tl or ideas on it. Thank you.

 

I haven't heard such a noise coming from my '99. The lower portion of the rear seat is really easy to pull out - just a few bolts and a quick tug. It's covering the fuel tank area, so if you pulled the cushion out you could get your ear real close to the pump and see if that's really it?
Doesn't solve the issue but at least it'd let you confirm.