My Trooper's mileage seems to be getting worse. It has 120K miles on the clock, and AFAIK oxygen sensors have never been replaced (been driving it since 98K). I'm thinking about replacing O2 sensors - how long exactly are those supposed to last? Also, Alldata shows sensor's pigtail being kinda round, but all sensors I've been able to find online have rectangular plug type. Does that mean I'll have to splice the wires and re-use existing plug?
Advice appreciated! Peter