Just a repeat:
The Viper engine, engineer, (yup-the engineer for USA) told us not to run the 02's in a single cylinder as it would definately confuse the computer. But then again, we have 5 tubes
Ist DV we made a 1" solid plate, drilled the 5 holes then on end drilled and tapped for the 02 to read all five pipes prior to reaching the collector. A sandwhich plate if you will.
All subsequent DV's including the DV II are using short headers, allowing us to use a long one piece elbow right into the sidepipes. At the very end of the headers is now where we are installing the 02's. So far this seems to work out best.
Bottom line, keep them close, better yet keep them close and reading all 4 tubes.
DV