Alright so I've noticed a large blow to my mpgs latley and confirmed it this past weekend putting in 10 gallons on E and reset the trip meter, My fuel light came back on at 132 miles. This is 95% city driving and I drove it like a grandpa. I even caught a few birds from other as they speed off around me. I pulled a 17 and 21 from the flash codes.

I know 17 has something to do with the engine not reaching temp within a certain amount of time. It does have a new thermostat and seems to take the average amount of time to warm. I do let it idle in the drive way for 2 minutes before I set off and by time I get out to the main road its at about a third of the gauge where it sits steadily. So any ideas on hpw to get rid of this? New temp sensor? Complete flush and refill?

I know 21 has something to do with the o2 sensor. I replaced it about 2 years ago if it's bad I hope my warranty is still good. I guess I need to get under there and check the connector for corrosion and voltage. What should it be at?

Would these two cause it to run really rich? Also it idles at about 1800 rpm doing 45 that is pretty high to my knowledge ill try adjusting the tv cable and need to check the fluid although I have no clue if atf level will affect the cruising speed.

 

I have also not done any modifications during the time of the decrease in mpg.