Bad Gas Mileage

I have a friend with a 4 cylinder 2000 Rav 4. Mileage is only about 4 mpg. No Check engine light runs a little rough pulling a hill. Anybodyhave any ideas?

Thanks

Yeah check of gas leaks.

If he hasn't yet, clean the throttle body with a spray cleaner, change spark plugs/wires, throw in a bottle of injector cleaner. Beyond that, a sensor could be throwing the timing or fuel/air mix out of spec ie, maybe a slipped timing belt/chain or a worn O2 sensor. Many, many possibilities.

passed message to friend. If and when they get it fixed I'll pass the results on.