My 1999 3.3L Caravan seems to run well but fuel usage has increased. I found instructions on the web that enabled me to display error codes on the electronic odometer but Its not clear what they mean. The codes are 23 and 55, and that seems to indicate a bad temperature sensor in some models. My manual lists the 1999 error codes as a different format (a letter and four digits), and the 3.3L engine doesn't have an air intake temperature sensor. Any thoughts would be welcome? Thanks Larry