does anyone know precisely where to put the o2 sensor? I am making my own downpipe and i need to know where to weld the bung in at. Also i know the egt probe goes in front of the #4 runner but does it matter where how far the probe is? Like should i just drill the hole right in the middle of the #4 runner. I bought a cast iron manifold off of ebay and was wondering if its thick enough so i dont need a bung? Do i need a bung for that manifold or no?

Originally posted by 95eclipseSlow
does anyone know precisely where to put the o2 sensor? I am making my own downpipe and i need to know where to weld the bung in at. Also i know the egt probe goes in front of the #4 runner but does it matter where how far the probe is? Like should i just drill the hole right in the middle of the #4 runner. I bought a cast iron manifold off of ebay and was wondering if its thick enough so i dont need a bung? Do i need a bung for that manifold or no?

The o2 sensor should ideally go as close to the header outlet or turbine outlet as practically possible. The faster it warms up, the faster it reacts.

The tip of the EGT probe should be as close to the center of the exhaust runner as practically possible, and 3-4" from the exhaust port of the head.

pictures?

Originally posted by 95eclipseSlow
pictures?

Wing it. it's not an exact science. The world is not going to implode if it's not 100% perfect and right.

here's some examples of an egt sensor mounted

<a href="http://www.ringo.com/photos/photo.html?photoId=240232410"><img src="" border="0"/></a>

<a href="http://www.ringo.com/photos/photo.html?photoId=240234016"><img src="" border="0"/></a>

Now are you talkin about a widebans O2 or a N/B? cuz thats about the only time a mounting location makes a difference.

Here's a look of mine on the star mani, should be basically the same for the cast manifold you bought. (Please excuse the ugly piping, ugly wastegate and the dirty valve cover they've all been replaced with better looking parts, although the tiny air filter is still there.)