Hi Scotty.  I have a 2009 Ford Ranger XL with about 106k.  The truck is running great and I just had a brand new exhaust system put in about 5 months ago.

Although I have two sounds coming from which I cannot find the source.  I am having it looked at for scheduled oil change and tire rotation in a couple weeks where they will address the noises too, but I want your opinion.

1. Moderated hissing noise when accelerating when driving.  Specifically around 1500-2000 RPM.  Anything over about 45mph there is no sound.  And it doesn't sound per say like engine is struggling to get fuel or air.  No stalling either.  Steady change of gears and accleleration, but a definitive hissing. Is this a vaccum leak indication?

2. Harmonizing/humming noise coming from bottom of vehicle to my knowledge to be coming from gas tank.  All troubleshooting leads me to say that is the fuel pump, but I am not experiencing any issues and the cause of the noise is completely random.  Sometimes I don't hear it at all, but you cannot hear it when I am driving at all, just idle.  Research shows that older models of Explorers and Rangers just have louder fuel pumps and in general; this may or may not be an issue... but what are your thoughts?

Drew 🙂