Thread: Incredible drop in mpg

Can your 02 sensor be bad and not give you a check engine code? The reason i ask is because im only getting 13 mpg instead of my usual 18-22, and i have done a tune up and oil change. Any other suggestions please let me know. Thank you.

What did you do for a tune-up? The O2 sensors do get old and die; they are a maintenance part. If you can get a scanner, that would help you find anything out of wack. Also, check that IAT sensor. If that is bad or disconnected I believe it defaults to some very cold temperature, like -60°F.

could be your 02's... probably is. 02's never avtually die unless they are fouled up. they get lazy, scan and look at the chart for the 02's. either that or i would say maybe your EGR..

For my tune up I changed the spark plugs and wires and air filter, as well as doing a full oil change.