P0136 code - can I wait?

[mainemetro]

'96 Metro, 1.0L 5spd, 69k miles.

This code, P0136, O2 sensor circuit Bank 1, Number 2 , suggests thet there is some problem with my downstream O2 sensor (after the catalytic converter).

The car drives fine, though I have seen a slight drop in MPG, but that could easily be due to the onset of colder weather.

I would like to wait on this issue because a cat converter and exhaust pipe replacement (due to rust) will be due soon.

What I would like to do is drive this as-is for a month or so until I replace the front pipe and converter - does sound like an acceptable plan? Does this "downstream" O2 sensor have any MPG or driveability issues associated with it or it is simply an emissions matter?


Thanks in advance!

Ren