HELP! Still can figure it out!

[texasstroker]

Still have my low mileage (51-K miles) 1997 Powerstroke with miss at idle and hard shifting at times.
First found it had bad fuel, have run it 3-k miles with different treatments and 5 new filters.

Have run the buzz/con test 3 times total now and everything show to be working fine with a code of P1111.

Run test on transmission found NO CODES.

When driving the truck a little hard it act as if the air filter is stopped up or like the exhaust is plugged up. Removed cat and muffler (no help there) Opened top of air cleaner and does not seem to suck air like my other trucks do! It is pulling some air in, but when I removed the top of air cleaner of my 277-k mile 1997 Stroker it will suck you hand into it.

I can idle the truck up just a little and seems to run better.

Forgot to add, truck has NO SMOKE!

[sk3322]

[texasstroker]

IS there anybody out here that has any clue what could be wrong or what else I can check?????

The local mech said valve guides! But anytime I have had valve guide problems I ALWAYS had smoke! This truck does not smoke.