Long story short, my Service Engine Soon light came on. Due to a bad experience about 30 years ago which would have cost me about $400.My brother in law called BS on the code reading I received from auto dealership at a cost of $68. The reading stated my MIP, O2 and some other sensors were toast. Brother in law reasoned all those sensors going at same time was not possible. He figured correctly it was my gas line filter being plugged which would cause all sorts of false readings. He replaced it for me, total cost was less than 5 bucks. My mechanic said it would cost $70 to $100 just to get a reading so I decided to buy the OBD2 scanner. I plugged it in where indicated and had my reading in 30 seconds. I had a Evaporative System Leak (small). Checking online the most common cause for this failure code is a loose gas cap. Last time I filled up I was in a hurry and screwed up screwing in the cap. The scanner is easy to use, allowed me to erase service engine light on my dash and saved me $$. Please note that some Auto Parts shops will do a code read free of charge.