I had the same issue when installing my long tubes. I burned up both o2 sensors at the same time. I went with NTK corvette rear o2 sensors for my pre cat o2 sensors and never had an issue.

 

i bought myself a welder, and i decided to weld in a bung where edelbrock attempted to put theirs on the left bank header. it definatly runs a lot better and i havent burned out any sensors. my fuel economy is up to 19-20 mpg and that isnt driving conservitivly, and with a bad fuel spider