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Discussion Starter #1
So a week ago, I pulled out my (replaced october) O2 sensor, only to find it was bad and causing my CEL to come on. I went and replaced it to the tune of $130 and it ran smoothly with no warning lamps. Just now after I went out for a jaunt to try out my new Euro headlights, suddenly the light comes on. Diagnostic tool again said 17 blinks=f*cked O2 Sensor.
Did it just eat an o2 sensor in 135 miles? Should I be looking elsewhere for faults in the wiring? Or are my EGTs somehow getting so high they're cracking the ceramic inside the sensor?
 

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1985 500sel and 500sec 2012 E63 1989 Porsche 911
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i wonder if my car even has a cel
 

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1993 300TE, 1995 E320 Wagon
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I'd check the connections first off. I don't know if there's a fuse that controls power to it-- could it be something like that? I highly doubt that it "ate" an O2 so quickly-- unless it was faulty to start with. Did you get a Bosch OEM one or something else? I recall that you can also use the same type for a Ford Mustang (cheaper to replace). If you have the OEM Bosch, it might just be that the connection under the passenger rug never got completely connected (I recall a pretty decent *click* when I pulled mine out a couple of years ago).
 

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Discussion Starter #4
No sir, I made very sure I got the OEM Bosch 13146 unit. I'll take a look and double-check my connections. I hope the unit isn't defective, because the one I pulled out was a defective unit my mechanic put in.
 

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1993 300TE, 1995 E320 Wagon
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Just to make sure, I wasn't implying a cheapo replacement or that you might be cutting corners-- I have a non-OEM unit in there myself (a four-wire unit that works just fine). At the time I was replacing mine, I read here on this forum that the OEM Bosch was not worth the extra $60-$80-- and a four-wire unit gives a faster/more accurate signal to the engine controls...

That being said, I hope it's just your connections... I will have to dig some, but I know that there is a test procedure to check on the O2 operations. Gimme a bit and I'll try to look it up.
 

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Discussion Starter #6
That being said, I hope it's just your connections... I will have to dig some, but I know that there is a test procedure to check on the O2 operations. Gimme a bit and I'll try to look it up.
Unfortunately no. The connections were solid. My dad, however did a bit of research and found that a faulty EGR valve would damage an O2 sensor, as well as produce several other symptoms we're experiencing. I pulled off the EGR valve and sure enough, it wouldn't hold vacuum at all. So I've got some new parts coming in the mail.
 
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