No. Think like this now. Px= 0 and Py=1 i.e. i now make good x to be a free good. Agent 1 now has zero income.Take this case now(only an e.g.): Agent 2 will prefer to consume (999,999) than (999,1000) since good y is costly as he needs to minimize his expenditure. Agent 1 will not consume the excess of good y since he has zero income and good y has a price attached to it. Hence, such a price combination results in a pareto inefficient allocation