On my 1995 at highway cruise in the 1600 to 1800 rpm range with a manifold vacum of 11 to 8 inches Hg my Actron OBD-I Scantool shows the spark advance is quite high: 42 to 48 degrees BTDC. I think this is because EGR slows combustion speed and requires more advance. I have even seen as high as 52 degrees.

I do not know if the OBD-I pcm is “smart enough” to not dial in this much advance if the EGR is not functioning.

Chrysler did away with EGR in 1996 when more efficient 3-Way Catalytic converters became available.
Non-CA EPA Tier 1 regs for the period 1992 -2003 can be met without EGR if the guts of the CAT are efficient enough. Light duty gasoline trucks over 3750 lbs to 5750 GVW only had to meet 0.7 grams/ mile,
versus the passenger car limit of 0.4 NOx grams/mile in that period.

Chryslers 1995 CATs were pretty fragile.
There was a recall.
My original factory CAT began rattling around 50,000 miles.

The 2nd dealer installed CAT suddenly failed around 110,000 miles and nearly plugged the exhaust. The extra backpressure blew out the internal bellows of the “EGR Modulating Valve” and I did not discover this until the first long trip on the aftermarket 3rd CAT. This is when my CEL light came on and I read the Ram FSM sections about how to troubleshoot and fix the EGR system.