Is there a zero tolerance engine in 1994 Dodge Shadow?

No, the 1994 Dodge Shadow did not have a "zero tolerance" engine. The term "zero tolerance engine" isn't a standard automotive term referring to a specific engine type or technology. It's possible you're misremembering or confusing it with something else. The 1994 Dodge Shadow used various engines, primarily Chrysler's own designs, but none were marketed or known by that name.