1998 Honda Civic Weird engine code

hi, I had p0505 on a few weeks ago then got the iac replaced now everything is good. So i deleted the code today and io checked the freeze frame data on the scanner at autozone the obd 2 one somthin like that. I saw something under freeze fram for p0309 which is cylinder 9. This dont even make sense my car is 4 cylinder. The guy there thinks maybe a bad connection. What do you think?

also im gettin around 26-28 mpg is this right. I believe i should be gettin 30+ my old corolla got over 30 with a 1.8l engine this is a 1.6. I drive the car normal too and easy on the gas.