Hi Scotty, 

Happy New Year. 

I have a 2015 Toyota Camry with 90K mile. The car working with zero issues and there is no warning on the dash. I purchased a test devise The BlueDrive just to check the car. The BlueDrive devise shows a code issue: Startability Malfunction P1604. when I saw the code, I serviced the car (oil change, engine air filter, new Toyota OEM spark plugs, and added to the fuel tank Toyota' injection cleaner) and I deleted the code but again it is still there. I will appreciate if you could advise if there is anything I need to check because from internet research it could be so many reasons (please note I never replaced the fuel's filter since I bought the car new!). thanks