[extremity]

Technically, listening for a hissing sound is the easiest method of vacuum leak detection. The next step involves injecting smoke into the engine via a smoke machine. If the truck runs bad I would assume low fuel pressure or major vacuum leak.

The 'chilton' list is BS as I diag problems like this every day. Lean on a Chevy means air/vacuum leak, low fuel pressure due to fuel pump, or bad airflow sensor or connection to. Once in a blue moon I see a bad oxygen sensor. I do not know if your engine runs fine or if you hear any hissing noises from the engine...