low gas mileage on 2002 Lexus RX300

why my gas mileage on my 2002 rx300 is going down, now to 14ml per gallon (from 16.9) even though i am changing oil, checking tires etc; water pomp, all belts have been changed and car has 95000 only
what could be done to improve
thank you for your help

Asked by for the 2002 Lexus RX300
Hello i have a question about when you noticed the fuel milaqe drop was it before or after the water pump replacement due to the timing may be out of factoey specs.I need more info and i can help.
Hi, I noticed fuel mileage going down before i changed timing belt and pump: timing belt was replaced professionally and it was the bey st one i could buy in town, by now the car has 13.9 only, i am planning to change plug and filter next week, looking for honest mechanic around i live in concord Appreciate your kind advice!
thank you
Hello i would recommend to replace the spark plugs if not done and have a fuel injection system flush,also have the throttle plate cleaned due to there may be carbon build up.I must also ask where and when are you filling the tank just remember all stations will not have the same refined gas.
You've been playing with this for four months? Really? When I answer a question for someone I expect them to follow through with the recommendation or ask follow-up questions to corect the problem.
3 answers 3 comments
Your air fuel ratio sensor and oxygen sensors are also wearing out. Check your MAF as well. What does changing your water pump have to do with anything? Did you recently having have it along with your timing belt changed? I would want to check the timing marks.
air filter, change plugs, and have the timing belt checked. if the timing is off from worn belt, mileage will be effected.

Roy