Hi Scotty,
I have a 2012 Toyota Yaris LE Hatchback. I notice the fuel economy of the car is lower. The mass air flow sensor eom is new, Throttle bottle is cleaned and fuel injectors work. Gas tank is fine and the gas neck and hoses and relay is good to. Can a bad fuel pump give off a code if a scan tool is use or does a bad fuel pump not trip a code and does it the gas pump need to be replaced or gas filter? Looking forward to your answer.
Thank you
How much lower is your economy?
I presume you would have changed the air filter.
The best way to diagnose this issue is to run some diagnostic test.
You would feel it if the fuel pump wasn't working properly.
Air filter was changed and spark plugs as well. could a dirty fuel filter cause problems to?
dirty fuel filter would give same symptoms as bad fuel pump. (significant lack of power, and hesitation)
make sure you don't have any exhaust restrictions. And Scotty has a few videos about how to make your car run better.
I would start with the fuel filter first. It could easily be causing your issues and would not trigger codes.
