The last oxygen sensor on my 1993 240 sedan lasted only two years, and now it needs replacement. It was one of the lower priced units, $35 from the local parts house. Before putting in another of the same, would it be wiser to put in one of the expensive $120 oxygen sensors? Other than the longer wire harness that comes standard with the higher priced units, is the sensor actually better, too? I mean, is it actually worth the added cost? Two years for the last, cheap sensor seems like a real short lifespan, wouldn't you say? Daryl