Turbo?

On my 855t I had this symptom twice and CEL for 02 sensor, lean, sensor out of range and other messages I've forgotten.

Turned out to be a vacuum leaks. Both times on the vacuum tree under the throttle cable bellcrank cover to the right of the intake manifold. First one was a broken nipple on the tree and the vacuum line hanging loose.

Second was more interesting. The engine was idling very roughly and occasionally was hard to start. But, with the cover taken off the bellcrank pulley it wouldn't start at all. I noticed in the cover a polished place on the plastic where it sits over the tree and sure enough, found a dime sized hole worn into the back of the vacuum tree. A new tree fixed the problems and only cost a few bucks at FCP Groton.com

I've tried adding a link to a picture below.

Good luck,

Erwin