Cadillac Repair: 1996 Cadillac STS Service Engine Light ON and OFF, mass air flow sensor, mass air flow

Question
Hi I have recently purchased a used 1996 Cadillac STS and I have been experiencing the "Service Engine Soon" light comes on and off.  I found through this sight how to pull the engine codes.  I was wondering if you could let me know what the following codes mean and if I should be alarmed.
I know one of these code have to deal with the Ride Control..(i think)
RS0021
PZ2719
PS0101
PS1406
IP1910
Also what does "Service Emmissions System" mean that pops on and off as well.
Thanks so much, I really find this site very imformative! :)

Answer
RS0021 = Left rear actuator for the suspension is under current.

PZ2719 = Trunk tamper switch is inoperative in the trunk.

PS0101 (if this is supposed to be PC0101) = Mass air flow sensor out of range.

PS1406 = (if this is supposed to be PC1406) = linear pintle valve of the EGR out of range.

IP1910 = Generator (atlernator) "L" tyerminal has open circuit problem.

They need to be fixed. For miltiple pictures and Directives, E-mail: cadillactech@hush.ai