Why did the check engine light come on recently in a 2002 Avalon with 38000 miles and no apparent problems at all?

Answer 1

there is a problem with the emission controls in either the engine, fuel evaporative, or catalytic converter system. its fairly inexpensive to check ( maybe 70.00) its useless to try and guess as there are perhaps 30 different possibilities within the systems. the car should be diagnosed with an obdII scanner and repaired by following the repair manual instructions

You can go to almost any national auto parts store (Advanced Auto, Kelly, Pep Boys, AutoZone) and they will read your computer for free and tell you which part is faulty. You can either buy the part from them and have it installed, order the part over the internet.

However, if you take your car to a dealer tell them exactly what you want done or the dealer will charge you about $50 - $90 to read you computer (which you have just gotten done for free at the parts store).