98 intrigue losing rpms while driving

I have done a extensive tune up on my intrigue, I have been having a problem last six months or so with it losing rpms while driving, idles fine and only loses rpms while foot is barely on peddle, If I give it more gas jumps up to normal, any suggestions what may be causing this?

Any codes set? Code can be set without CE light on.....

Have access to a scan tool? Check TPS data as you open throttle....