American cars were required to have catalytic converters since 1977 (or was it 1978?), so yes this car has a cat.

The more important question though - does this car have the warmup delay? I thought this was a later thing, not applicable to the early (Gen 1) cars?

If it's a slip/flare especially under moderate-hard acceleration, look into the K1 spring. Mine was broken in 3 places in my SDL and the difference in shift quality was nothing short of stunning once it was replaced. 2-3 shifts happen a lot, especially in city traffic, and craptastic shifting gets old FAST.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)