engine vibration

So does the engine miss At idle and smooth out his off idle? It sounds like you have low compression in one or more cylinders lets run down this guide to confirm the issue.

https://www.2carpros.com/articles/how-to-test-engine-compression

Please run down this guide and report back.

the engine seems to be hunting revs at idle and then gets smoother as i step on the gas.

Have you checked for vacuum leaks yet? this guide can help us

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

A vacuum leak will not effect the compression. You said there were no codes no you say you got a code then replaced a sensor for it?Was there a code set that made you change the sensor?If so did the code set again? What wAs the exact code number not code description if it set a code?If you unplug the idle Air control valve And it stops searching At idle you know that's one reason its doing that. If you lightly tAp on the mass air flow sensor with a screwdriver handle while its idling does that change anything?Also what size engine do you have?

computer report had shown an intake manifold sensor fault.
changed the sensor. but the problem persists.

where are the relevant vacuum pipes located in this vehicle?
and would that not show thru as lower compression in the engine? all cylinders have normal operating pressure according to my mechanic. MAF was also cleaned.

I did the compression test and you were right had 40 psi in #3 cylinder, time for a valve job.

Nice work, we are here to help, please use 2CarPros anytime.