I was looking at a MS 2 with an oxygen sensor when it occurred to me the stock exhaust for my oversized 1.7 has header pipes that never come together for a place to locate a single or dual oxygen sensor. Please share any thought or location you have found to place a sensor or two sensors.
Thank you in advance.

Work out which cylinder runs the leanest, and use the runner for that one. If you're using split intakes, pick one from either side...

I would put it on #3, it runs the hottest.