Recently I read a good article in the January issue of Strar Tune December 2005 volumn 5 number 5. The article goes on to decribe early 02 sensors and the new wide band planar sensors . the difference is that instead of ceramic thimble, heated planar sensors utilize a flat ceramic zirconia element, less than two millimeters thick, projecting into the exhaust stream. The electodes conductive layer of ceramic , and heater are laminated into a unified layer strip. This strip is smaller, lighter and more resistant to contamination than the thimble design. The planar sensor intergrated heater element also requires less electrical power to reach operating temperature. that is the real advantage when you consider the number of amps necessary to bring a heated thimple type up to the 600 deg. F. required.

Some discussion was breifly discussed but not finalized as how to properly test
o2 senors. Mercedes-Benz does not recommend any avasive test that can comprimise the ground wire by probing. what other ways are safe to test these senors?
Bob Geco