I have a 1991 Pickup 4WD 22RE with 110k. my MPG is around 17 or 16 and when i get out of the truck from driving around I smell like a lawnmower. Anyone have ideas on possible problems? I just replaced my Oxygen sensor thinking that would fix the problem. could I have an exhaust leak upstream from the O2 sensor? Thanks

 

If you have fuel odor, you probably have a fuel leak. Check the pulsation damper - disk on the underside of the front end of the fuel rail. Also check the rubber section of the fuel return line from its attachment to the side of the fuel pressure regulator to the hard line leading to the tank, and check around all injectors, including the cold start. If the fuel smell is back by the tank, it's either the rubber section of the return line leading from the hard line to the tank, or, more likely, rusted fuel line where it comes out of the fuel pump bracket.

There are plenty of sources of ignition on a motor vehicle, especially in the engine compartment, so I wouldn't drive it till you find & fix it.

 

Thanks for the ideas. I figured it out. HUGE exhaust leak coming from the gasket where the manifold meets the down pipe. i guess it was exhaust i was smelling and not fuel. I'll replace the gasket and be good to go.

 

Congrats on finding the leak. As it seems you already know, exhaust leaks can allow extra oxygen to be drawn into the exhaust stream, causing the O2 sensor to falsely report a lean condition & the computer pours on the fuel to compensate, causing it to run way too rich & causing poor gas mileage and stinky exhaust. With luck, your mixture should get back to normal after you fix the leak, and your mileage should improve too. Please report back to let us know.

 

Fuel odor? Fuel leak.
Exhaust odor? Exhaust leak.
Coolant odor? Coolant leak.
Valve noise? Turn up the radio!!! LOL.