I've had a P1457 on a 1998 we used to own. It did not put the car into "limp-home mode" and it absolutely did not cause any sluggishness. No real symptoms at all other than the light.

In my case the problem was a rusted-shut valve (the "vent-shut" valve). That valve is used to allow the system to test whether the canister is airtight. It occasionally does that test, in compliance with EPA requirements. That particular valve failure doesn't affect the operation of the engine at all.

If the canister were actually cracked, not airtight; THEN the engine operation might be affected along with setting P1457. Just saying that it's possible to have P1457 with absolutely no affect on engine operation.