also make sure the IAC is clean and free of carbon build up.
if it were me, i would sea foam the top end, clean the TB and sensors with intake cleaner, then get some new plugs. maybe even a new fuel filter. all as precautionary measures for the future and to rule out most of the causes of rough idle. all that doesnt cost more than $30 btw.
1996 with 254k miles, L32 4" FWI -> ported N* -> Ported Gen V w/3.0" Pulley, Stage 3 Phenolic I/C, ZZP FMHE, 1.84 RR, Headers and 3" pipe to mufflers, F-body brakes, and lowered on Eibachs. -RIP
AMG C400 White on black -daily