RL with flashing D4 tcs and never ending EGR code

my sister have 97 acura RL (canada model) she have this never ending check engine light..the light is for EGR code ..egr was replced and passage was cleaned out at intake manifold ..but still the light would come on after a few hundred of miles after the code was cleared..and also the gear indicator at cluster woulf flash D4 now and tcs light come on ...the indicator will not flash if you shift from park and go directly to D4 or D3 and tcs light won't come on either..the light would come on only if you glide into neutral or reverse then the D 4 flash...iam at a dead end ..please help.