Put your hand around the exhaust as much as you can then and you should feel it or hear it. If it's before the sensor, then it can only be the turbo or manifold that's blowing.
Having said that when my turbo was hanging off, it ran fine, just noisy.
So here's an update after having spent a day on the car ... No apparent exhaust leaks so the readings are accurate and I was sure they were because I feel the stumbles. I figured I'd check my fuel pump voltage and I'm getting 12.1 on idle which is something ill have to sort out. No apparent vaccum leaks and cylinders are showing 167 psi of compression on all 4. Another problem I stumbled upon was my tps sensor ... It was set to 0.45v but in WOT would only reach 3.8v so I figured why not swap it with another one I had laying around but same rthing. The only way I could get it to 4v in WOT is by setting it to 0.54v on idle ... Something is wrong here but what ???