Okay so right now I have my o2 sensor for my zeitronix after my test pipe where the rear o2 sensor used to be. Is that too far downstream to get accurate readings?

That is where mine is too.

After the test pipe is ok, it's where i originally had mine, but it may suffer from slower response at lower engine speeds. Not a big deal if you are not using the wideband to run the engine with a Megasquirt or other standalone..if you just want to read WOT AFR's, it's sufficient. For fastest readings, it's best to keep it within 3ft of the exhaust manifold. Stock front o2 location is a good choice, which is where i have my wideband(i replaced the stock one since i'm using the megasquirt). Most wideband manufactures recommend a minimum of 18" from a manifold or turbo outlet to keep it from seeing too much heat.

I have the WB output fed into my MS, but i'm not using ego correction at the moment, would it be better to put it in the single o2 sensor bung on my hrc 3" dp?

I'm guessing I should move it to the downpipe to get more accurate reading for tuning my cruising af/r's. Any input?

If you are going to control closed loop fueling with the Megasquirt, i would really put the wideband in the downpipe, close to the stock o2location by the oil pan. It's not *imperative* that you do this, but it would be best to.

My stocker and Wideband at appx 8" downstream of my turbo. I moved both closer since the recommendation from Techedge was 11-14" from the head.

I had some documents from AEM when I got their WB controller setup that for turbo installs they recommended some crazy 34" to keep it from overheating... That's around where I put it (around area behing RH half-shaft), but I think it's way too far back. MS seems to constantly play catch-up, makin it surge around idle, irregardless on using ms steps or ign pulse. I can tune a ms step to work great, but then all other RPM's are shot. Gonna try moving it to the original O2 location and see if that helps. I remember on my GN the damn O2 was close as hell to the turbo, like 2" on the DP... but it wasn't a heated O2, if that'd matter.

See thats why i dont run an AEM. the sensor you have is the same one I have but with a different plug. I never have issues with mine overheating or reading inaccurate.

The AEM documentation also recommends that you tilt the tip of the sensor down a few degrees so that deposits don't form on it. So when you weld on a bung, it should be at least someplace where the downpipe is not vertically oriented. Food for thought.

Just philosophizing...-> It seems strange that moving the sensor that distance would make a noticable effect on MS monitoring. It would think that the high velocity of the exhaust gas would minimize the impact of such a small distance. Also, I wonder just how much EGT goes down after 36" of travel. Every recommendation just seems so arbitray - how can we know what is optimum with so many variables that come into play?

I know EGT goes down quite a bit, evident in the fact that my exhaust wrap burned off the silicone paint stuff but fades to the cheaper hi-temp black that i coated the last half (just about at the half-shaft). Terry, you said you're not running the AEM for the overheating reason, but use the same sensor? how's that work? Or is it something the AEM controller does that's crappy (besides constantly randomly changing output modes)?