2001 silverado when accelerating truck almost sounds like has a exhaust leak but is not a exhaust leak any ideas

Try the maf sensor or fuel pressure regulator, if you have no exhaust leaks or timing issues.

yes could very well be an exhaust leak.but that should be kinda loud and annoying..also u could have a slight whistling sound coming from ur air intake hose coming from air cleaner box to ur intake or throttle body or ur air inlet goin to the motor. when the motor is accelerated it would produce a high pitch sound like a whistling .hope this can help

Vacuum Leak or bad fuel or fuel pump

Have u checked your exhaust for any leaks it sounds like it has
a small hole or even your exhaust manifold!

not the knock sensor . maybe exhaust leak ,possible lifter

WEll, it certainly can be an exhaust leak. Take a heater hose and hold one end up to your ear and probe around with the other end. Exhaust manifolds are a big issue, these days.

Check the EGR valve pipe connection and mounting gasket, also check the EGR pipe connection at the exhaust manifold. Check the exhaust manifold for cracks and gasket leaks, hope this helps, let me know.

Lift it and take a closer look from under beneath, asking assistant to do a some acceleration..

check for a wet tailpipe,which might indicate a leak between water jacket & combustion chamber.i.e.headgasket.check heater hose isn't leaking onto exhaust manifold,'cooking' the anti-freeze as it leaks.

This may not be your problem, but recently we had chevy in with a ticking on acceleration that turned out to be a leak on the right hand exhaust manifold only slight but enough to make a noise when driven hard. we noticed a carbon mark around the second cylinder in. If it is a petrol engine have you checked the spark plugs are correctly torqued?