200 miles on 11 gallons.from full to the empty.
So are you running the tank dry?
Because according to you you're getting 18 miles per gallon. That's V8 gas mileage for sports cars. You'd have to be throwing a lot of codes in the rare event that happened. Driving this car would be uncomfortable and the car would probably be bogging.
Here's what I want you to do (just want to make sure you're really doing it right).
Reset your tripometer each time you gas up.
Gas your car up and get a receipt.
Write down the miles recorded on your tripometer on the receipt.
Now look on the receipt for how much gas you just pumped in.
For example, say the other day I gassed my car up. I gassed it up far before the tank was empty, but I can still tell
exactly what my gas mileage is, even without looking at the gas meter.
So I drove 188.9 miles (from tripometer).
I put in 5.179 gallons of gas.
So 188.9 (miles driven) divided by 5.179 (gallons put in tank) equals 36.47 (mpg).
So (miles driven) divided by (gallons put in tank) equals (mpg).
So 36.47 is my miles per gallon.
The tank capacity means NOTHING unless you ran the tank totally dry.