Original owner of 2000 Avalon XL. Cream puff condition still with 124,000 miles. Last year the engine check lite came on "Mass air flow sensor" got it replaced for $240. Nine months later, lite on "Oxygen flow sensor" two of them had to be replaced. Cost $520. Still the lite is on!!! Now, they tell me it could be the computer board!!! Can't wait for that bill. I've always gotten 25-26 MPG, now I'm getting 35-40; hope my engine doesn't burn up!!! What the heck is wrong???

Please, someone help me...

Update from Jan 21, 2011: Tire co. Olin Mott replaced my valve cover gasket; their "best" mechanic failed to attach the ground wire to metal. Toyota dealership found, after two hours of tests, it attached to plastic! That's why the engine check light stayed on and the computer kept reading two oxygen flow sensors were bad. Twice Olin Mott insisted I needed 02 flow sensors, then I took the car to a second shop, they replaced them TWICE just to be sure. He realized it was an electrical error and sent me to the dealership; thank God they found it. Now that I've spent over $650 fixing Olin Motts error they called to say they'll give me $111 to cover the dealer. Pitiful customer service. Not to mention two or three tubes they did not reattach to the fire wall. DON'T go there unless you like training mechanics with your car.