Just installed a new timing belt and water pump. A couple weeks later I get a malfunction light. I have a code scanner put on it and it reads bank one oxygen sensor one and lean mixture on both banks. Now it shows both O2 sensors. Everything looks like it was hooked back up and buttoned up correctly. Any thoughts? I highly doubt both o2 sensors went out.

 

Hook your scan tool back up and check your o2 readings and fuel trims. If they stay lean at idle but when you open the throttle they come back to normal there is a vacuum leak somewhere. post what happens