1997 Chevy Camaro Oxygen Sensor

I recently bought a flowmaster cat back exhaust system and I have a problem because in my stock exhaust there was a hole for the O2 sensor and the new flowmaster that I purchased doesn't. The hole was right before it reached the catalytic converter on the stock exhaust. My problem is I am not sure where to the drill a hole for the O2 sensor on the flowmaster? Here is the website that shows a picture of the exhaust system that I bought and I was wondering where I should drill the hole can anyone help me?

http://www.autopartswarehouse.com/details/QQChevroletQQCamaroQQFlowmasterQQExhaust_SystemQQ19951997QQF1317357.html