How do I locate the fuel pressure gauge on a 2008 Rav4?

Fuel pressure sensors may not be what many assume. EFI systems monitor fuel vapor pressure and vacuum in fuel tanks when emissions control programs test for leaks in sealed fuel systems while the vehicle is driven. Less than 2 psi of vapor pressure and low vacuum is measured with a combination fuel pressure/vacuum sensor mounted on the fuel tank. OBD II systems on USA marketed vehicles perform emissions testing every time the engine is started and during vehicle operation.