Hello Scotty long time viewer..
2019 Toyota carrolla SE sedan CVT SHE HAS 16,580 i was getting almost 45 miles to the gallon when i 1st got her and now it droped down to 33 do you think my mas air sensor is dirty?? Also i have a new battery just installed new airfilter synthetic 0-20 and great oil filter? If i clean my mas air sensor will i mess up anything with the computer? And will lights come on if i take the mass air off to clean it ??? Afterwards
No lights will come on if you take the mass air flow off as long as the car isn't running. Make sure you only use mass air flow sensor cleaner only when cleaning this. Chances are this is not your issue as the car is so new though unless you are driving in an environment with lots of fine dust in the air... it can drop that low just from how you drive it and if you are doing more stop and go rather than highway driving.
OW20?? Don't these things take OW16 or is that just the 2020+ models? Look into that. Also, where are you getting your gas? Could be bad gas. Go to another station and switch around to see if that makes a difference. Check your tire pressure to make sure they aren't all grossly underfilled.
