Will an aftermarket oxygen sensor fitted to a 1995 Jeep Cherokee Sport 4.0L 6-cylinder stop the Jeep dealer from being able to do a system analysis when the Check Engine warning light comes on?

as long as the aftermarket part is a DIRECT part number replacement for the factory one it should not make any difference at all...............good luck, Mike they will have a problem if you have a fuel ratio or o2 fault because replacing only 1 o2 sensor sometimes is not advisable. your pcm uses that data for fuel stratagey and is sensing the lack of oxygen in exhaust gases. it doesnt matter weather it was up or downstream, you should have replaced both at the same time to insure correct adaptive fuel ratios.