Die hard

Hello been while sin I've I've posted on here had to open new account/screen name ..
I have a 96 a4 2.8 with 454,000 miles (best car I've ever owned) this happened once for few minutes a few months ago engine was SHAKING UNDER ACCELERATION at low rpm's trying to push it to higher rpm's once the rpm's are up it clears up ( standard trans) so if I hold it in gear little longer before shifting up it pulls fine no shaking .well that problem went away for few months .now problem has come back ..engine has a very little rough idle revs up fine in neutral .under load when trying speed up engine shakes with power loss ? When I first scanned I had multiple codes but been while since I cleared em i cleared them had po170 fuel trim bank come back I cleared it went for 20 min ride no codes came back but engine is still shaking under load ? I sprayed starting fluid all around intake looking for leaks . i replaced spark plugs few weeks ago .i pulled coil wires off with engine running one at a time looking for change in idle witch they all did change .i have new rattle coming from cat. converter ? What would failing EGR valve do ? any one want to give me some suggestions on what to try .
Thanks for reading my post (I will post update with my problem when I fix it )