So I just installed an AEM UEGO Wideband O2 sensor about an inch before the flex section of my 3 inch DP. I installed it on an angle per the instructions and used the bung provided in the kit.

I believe this is about 20 - 22 inches from turbine housing, and now I've read many people installing further back.

How many people have had premature sensor failure due to installing to far up in exhaust stream?

Mine is right after the flex section but in retrospect I wish I would have put it farther up. Many people install the sensor in the front o2 location with no problems for years. Not that I would recommend it, but the sensors aren't as sensitive as many like to lead on. Where your sensor is mounted is just fine.

My wideband sensor is right below my firewall. I can see it when I look in the engine bay below the back of the block. Not sure if its the best spot but before my sensor died it read pretty good

Mine is in the area right in front of the xmember (below firewall). Its about as accurate as closer up but theroretically longer sensor life. Only thing that's been a problem is sensor response time, its about a second too late and I've had to compensate for it in tuning.

Mine is right behind the flex section basically below the firewall but a little further up. I plan on moving it to my stock o2 location soon, more accurate reading and I wanna do o2 simulation with it.

I just installed my aem wideband in the front o2 location and using it as a narrowband in place of the factory o2 sensor, working completely fine. If the sensor does go bad after a year then that's fine for me, I like the accuracy of it.

Been running my mtx-l in the stock front location for years with no problems at all. And I daily drive and race (drag strip) mine a lot. But I also calibrate mine before every race to insure it works perfect, so far so good.