2000 Avalon Starting Problem?

Yesterday, all of a sudden, my Avalon will not start. It has about 70,000 miles. I tried for several times. The engine actually turns. I can see the needle reaches 1000 RPM like it is going to start. But it drops back to zero immediately. And the check engine light will stay on.
It was towed to a dealer and they cleaned the throttle body. They also recommended to have the fuel line cleaned and engine de-carbon?? or something. Are these recommended work necessary? Thanks.

I doubt it. I'd get it to a real mechanic as soon as possible.