Hey Scotty,
first off I have to say I love your show! I have a 2012 Kia Forte LX with the 2.0L engine.
Over the past few months I’ve gotten really bad gas mileage like 215-230 miles per tank. I’ve been running Shell 0 ethanol gas for about 10 tanks now and no change.
The only symptoms are slightly down on power and bad fuel economy.
i also recently changed my spark plugs to see if that would help but it did nothing.
let me know if you have any suggestions.
Clean the MAF sensor and change the air filter. Did you check the tire pressure and brakes?
brakes and tires are good. I’ve had all air filters changed recently as well.
Also new symptom on cold start; pretty noticeable shake at idle.
What do the STFT and LTFT numbers look like at idle when you hook up a scan tool?