12 is batt disconnected- normal
33 is no A/C signal- normal
54 is bad cam sensor
55 is end of codes.
I would replace the cam sensor, and definitely replace the manifold gasket.
'87 YJ, 4.2L built and bored, 8.5" of lift, 8.8 rear, AX15/NP 231, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...