Alright so I have a 1994 5.0 f150 and I just replaced the IAC valve do to bad idling and that did not fix it now my truck is giving off a code 33 which I cannot find out what that is. Different websites are giving me two different answers some said "throttle positioner sensor noisy/harsh on line" and some of them said egr did not open. Can someone please help and figure out what these are..

 

Your truck will not have 2 digit codes, that code is for EGR not opening during running test or if memory has intermittently not opened.

Not sure how you are pulling your codes but 94 V8s have 3 digit codes. I personally don't trust the "automatic" code readers, the best way is to pull them yourself following the sticky on pulling codes that Sean wrote.