Seriously need help with.bucking issue.

I have a 2001 galant, 2.4. I have this weird issue where it will buck between 2500 and 3000 rpms and at no other time. Idle is fine, I checked the TPS with a volt meter, checked the EGR diaphram and voltage, changed the spark plugs, changed the IAC, cleaned the MAF, and checked absolutely everywhere for vacuum leaks, and cannot find the problem. I know it needs valve cover gasket and spark plug seels, could that cause the issue? I'm at a complete and total loss. could it be the MAP? Which is actually an MDP on the galant.

Yes it could, change the seals. If the leak is bad enough, you can keep changing plugs all day long, the oil getting on them will foul them.