View Full Version : O2 Sensors Problem **HELP** what to do???

06-05-2003, 07:55 PM
My 97 Cobra (96,250mi) has been having a very rough idling for a couple months and when I'm drving in stop and go traffic it will more than likely stall. The engine light has been on, and I figured it's because of having the h-pipe w/o cats. But at work I dynoed my car and it said "Low 02 sensor voltage". So I went ahead and looked at them and they all black and burned up, and I also happend to notice that they were originally from ford because it had a like a 8 or 9 digit number.

**So when I buy news 02 sensors do I have to match those numbers? and should I replace all four of them? and what might the price range be?**

** And what about MIL eliminators I noticed that they had a number on them (32 or 11) does those number need to match anything when putting on MILs or does it matter??**


06-05-2003, 10:12 PM
Mil Eliminators just bypass the code thrown by the rear two 02 sensors. That could eliminate you having to buy those I would think. As far as the front two, if they are bad then you could get some new from Ford or an auto parts store. I'm sure you could just tell them the year/model of your car and they'll give you what you need.

I think there is a seperate code for the front and rear 02 sensors though, make sure you know which ones are bad before you do anything about it.

As far as them being "burnt up", well when I remove mine they are pretty dark/black simply b/c of the exhaust gases. FYI they won't be pretty and shiney when you take them out so that may or may not mean that they are bad.

06-06-2003, 08:43 AM
If you replace the upstream sensors, there should be a calibration tag on the inside of your driver side door. Give this # to Ford. I would only use Ford sensors, there have been problems using aftermarket senors. The mil elim. will take care of the downstream sensors.