Exchange rate policy has its limitations, warns MAS

It can't completely contain inflation as it is not effective against housing rentals and car prices.

Here's more from MAS:

But there is a limit to how far we can use exchange rate policy to contain inflation. First, while exchange rate policy is effective against imported inflation and domestic cost pressures arising from rapid economic growth, it is less so against inflation in housing rentals and car prices. Even so, housing prices and car prices cannot keep rising rapidly in an environment of weakening economic growth.

The measures taken to address supply-side issues in the housing market and public transport will also help to ease price pressures in these two areas. Second, too rapid a rate of appreciation of the Singapore Dollar can significantly hurt our economic performance, especially in light of heightened uncertainty in the external environment.