Hmm, looks like the only way to tell the difference between nearrow-band and wideband sensors will be the part number... Looking around Denso Sales' page on Amazon, it looks to me like the narrow-band and wideband sensors all have 4 pins on the plug

I don't suppose you can read the part numbers on the sides of your O2 sensors, can you Dale?
http://www.amazon.com/s?ie=UTF8&keyw...%20Inc.&page=1