The wife's car needs a sensor swap according to a local mechanic (crappy fuel mileage recently).
I assume there was a check-engine light and a code?

It might be hard to cross-reference part numbers for the 1.2 and 1.6 (Rockauto is usually a good resource), because the 1.2 was never sold in Canada/U.S.

That's the route I would take: through online sources or your dealer, compare the GM part numbers for both.