3 o'clock should face the passenger side of a USDM car

Here's an example

 

AEM warns directly against this. Im sure it wouldnt hurt much but they say to not mount directly horizontal...


"On turbocharged engines the UEGO sensor must be installed after the
turbo charger, if not, the pressure differential will greatly affect the accuracy of
the unit. For accurate readings, the sensor must be mounted before catalytic
converters and/or auxiliary air pumps. To prevent collection of liquids between the
sensor housing and sensor element during the cold start phase, the installation angle
should be inclined at least 10° from horizontal with the electrical connection upwards."

 

I've always heard 3 o'clock and never have had an issue.

 

Just passing along AEMs instructions

 

Even the MAP downpipe on my Evo X has the wideband bung at 3 o'clock

 

As long as you drive a decent distance with each trip, the sensor should be fine. And if you have to drive short distances, then set your turbo timer to 5+ minutes. Lol

 

Ehhh, I've had the wideband on for a few years now and I've yet to have an issue with any amount of driving that I do.

Even the Perrin test pipe I have on my IX has a wideband bung (made it easy so I didn't have to add a bung into my downpipe). That bung is also at the 3 o'clock position

 

Guess condensation isn't a problem for you. Maybe it's because you're driving it hard to fully heat up your exhaust.

Isn't the stock rear O2 at 3 o'clock position in the stock cat?

 

Before I drive my car I let it warm up first.

And I have no idea, been forever since I've looked at or touched a catalytic converter for an Evo

 

I just searched and saw that oem is at 11-12 o'clock position.

 

I've thought more about where to install my UEGO bung. I'm going to look for a location further up from my cat. Maybe somewhere near the oil drain plug if there is enough room. I think having it too close to cat will blend the readings because of the flow restriction caused by the cat. I want to see it change per cylinder as gases flow by. Too close to cat will blend the readings which is more of an averaged reading. If the lean conditions of one cylinder is blended with the others running rich, we won't know how lean that one cylinder is really running until it's too late. (You guys running a test pipe don't have this problem). Thoughts?

 

you must mount it BEFORE the cat, as said in my previous post quoting AEM

 

Yes. There's a spot a few inches before the flange with cat.



Facing front of car from under cat.

And there's another opening near front right inner cv joint.



My concern with being so close to CV joint is if that boot rips off, it could destroy the UEGO sensor. But it's usually the outter CV boot that rips first.

 

Good thing I looked under my car. I have an oil leak somewhere and need to track down source later. Also, I have no idea where the downpipe got its discoloration from. Wasn't there when I reunstalled it last time. Maybe coolant leaked on it?

Found my oil leak. The oil return line to oil pan was leaking with new gasket and factory torque. I torqued it to 130 #-in. Hopefully this stops the leak.

 

Here are my bungs.



This is the one I'll try first since I will always have a cat in my car since I'm in California.



I will wire up the gauges when I get home later.