Actron CP9175 Well worth the money,

My daughters engine light came on in her 2002 Camry. She took it to the Toyota dealer and they said the catalytic conver was bad. The repair would cost $1100.
I purchased the Actron code scanner to verify what the dealer was telling her. The error code indicated her catalytic converter was below the operating threshold. I orderd a catalytic conver from the internet and replaced it in just over an hour. I reset the engine light with the CP9175 and she was back in business.
Not long ago the engine light came on in my 1998 Camry, I took it to the dealer and was charged $590 to replace the oxygen sensor. If I had known what was wrong I could have ordered the part from the Internet for $120 and and it would have taken all of 15 mins to replace.
Make sure the code scanner you buy will reset the engine light (this model will). The error code read out by the CP9175 is very basic, but that's all that is needed. It will let you know what sensor/area is causing the engine light.