That is why you have to change every 5k miles to avoid any risk. In general, Toyota has an issue with fuel injectors leaking. Thanks man for amazing video

No sure if they can program ECU to inject gasoline fuel during suction stroke when starting engine from cold. This will be inside of cylinder having slight negative pressure ensuring fuel is evaporated. When engine is hot enough ECU comand fuel injection before end of compression stroke. Fuel pump internal seal leakage can also contribute to fuel dilution.

Good idea. I’m running 0w16 and worried it’s too thin.

Did you do the analysis after a short trip? Seems strange an injector would be failing at that mileage, especially a port injector. Good idea to try a cleaner first and then retest. I bet it’ll be fine next time around. And you’re lucky if it is the injector - that it’s a port injector on an inline four cylinder - otherwise as you’re probably aware, that thing would be a nightmare to change.

I have the same car. Where do I go to get an engine oil analysis?

The Car Care Nut recommends every 5000 miles or 6 month oil changes. He said he's had so many toyota engines start burning oil because the owners of the vehicles went with the every 10,000 miles oil changes, I'm surprise your Corolla has held up with changing your oil every 10,000 miles