I purchased the exact replacement from amazon 80bucks.no splicing involved direct fit.I'll test some more tomorrow have to pick up wife from work.
if voltage is bad then they sold me a substandard sensor.if it test good than its either bad pre cats or plugged cat .car has 160k with original ex syst.but runs great.from what I've been reading here it would run like crap!
other thing might be running to rich or lean.there is an adjustment hole for throttle body on top of air cleaner, lambda screw.its never been touched and still has a plug over it
last resort
I like my old 78 Chevy truck its so easy to work on but not very classy like the Benz!!!