Hi everyone. My chceck engine light was on. So I went to see whats wrong with it. I got code P0141 which is rear o2sensor.
And my question is. Should I go and get one from dealer or buy one on ebay for 70$

 

www.oxygensensors.com ... look and search in the GD forum

 

I'd buy one of those fake O2 sensor boxes from ebay. The rear o2 is pretty much useless so spending $30 on the fake o2 is smarter than spending $70 for a real one.

 

Ha ha thats good idea too

 

I'm not sure why you're laughing.

 

Because why should i spent 70$ if i can buy fake o2 sensor for 30$

 

ok, I thought that maybe you thought I was joking.

 

Ok thanks. I will try to get fake one and pass emission with it.

 

The rear o2 is pretty much useless...[QUOTE] If the rear 02 sensor is bad. will it affect the cars perfomance?? What good is a fake one?

 

The rear o2 just monitors the cat converter. It's useless but won't let you pass emissions if it throws a CEL. The fake one just sends the correct voltage or resistance to the ECU telling it that it's working fine.

 

My mechanic called the rear o2 sensor"window dressing", Dave Sz already answered one of my questions reagarding passing emissions with a failed rear o2, but one I'm not clear on, is it also any indication of a failing CAT, would the o2 being throwing a code 0707 because the CAT is done and the o2 is fine or is indeed the o2 dead, I've been running around for a year with the 0707 code, because emission tests here are every two years. I have a new CAT or I am going to need a new o2 also? If so where can these "fakes" be found? It's seems the best buy for "real" o2's is at: http://www.buyoxygensensors.com/

Not meaning to take over this thread but I think some answers to these questions will help others on this rear o2 issue.

 

It could indicate a brokem cat. I just threw my old broke-*** high flow cat on a few weeks ago. It's broken cause the inner honey comb came loose. I was at an exhaust shop a few weeks before that and they have a poster of why a cat converter fails and what happens when it fails and for what reason. My high flow fell apart cause the exhaust temps were VERY high, discoloration on top of the cat shielding. My guess it that's it's the y-pipe's fault or a clogged EGR. I'm leaning towards the y-pipe though. Then again neither my current car's rear O2 nor my old car's rear O2 ever gave a code.

 

You should test the resistance on the 02 sensor first. Like Dave said, it could be signaling you that your CAT is bad.

 

I'm almost positive my CAT is bad or on the way out as I have over 200,000kms Canadian ( around 120,000 miles) and that's usually around their life expectancy, that's why I was asking