I have a 2004 Mazda Rx8 with 46,000 miles on it. I recently bought and installed a mazdaspeed intake and my check engine light came on after 2 weeks of driving it. The code is P0037. My mechanic told me that it was one of my o2 sensors and that i needed to replace them all. Is there anyway to figure out which o2 sensor it is so I dont have to replace them all? I have disconnected the battery for 20 seconds and reconnected it and then turned on the car and the cel did not come on. I drove around for a little bit and it still didnt come on, but when i shut the car off and turn it back on the light is back on instantly. Any info will be appreciated. Thank you! Have a great Memorial Day weekend.

 

If it is a P0037 it is the rear O2 sensor....the cheaper one

 

would that be the one after the cat?? I went to get the car inspected and it failed because of that code. And he is telling me that he has to replace all the o2 sensors because he doesn't know which one it is. In your opinion do you think the o2 sensor went because of the intake or just general wear n tear?

 

It's th one in the CAT pipe.....it's actually between the bricks of the catalyst...it measures the efficiency of the CAT when compared to the front WBO2 sensor

No reason the intake should have caused the problem.....a coincidence

They do fail...and they also have a tendency to melt the wires if anyone was playing around with them and didn't tie the wire up properly

I think they are $120ish to replace..not too bad really

 

2004? Funny I thought this was the series II section...

 

I just try and answer the questions

Usually leave the asshattedness to others

 

Luckily we have Ryan2008 to give the typical *** comments. The intake did not have a role in your O2 sensor failing. I have the same intake.. love it! No problems because of it.

 

My bad, I love being a smart *** lol no offense though to OP. I was just curious is all...

 

ok guys I have this same code and I have a brand new cat that mazda replaced under warranty...do you think this shoukd be covered by them?

 

^If the code indicated Cat failure I doubt that they would change your 02 sensors. The sensors give different codes. However, I totally agree with you...If you get a new cat they should change the sensors as well.

 

so if my cars throwing this code do I definatly need a 02 sensor or can it be taken out and cleaned? Anything else that can make it throw this code?

 

You can clear it out but I am sure that the CEL will come back at some point. Sooner or later you will need to change the sensor. I am not sure what causes the 02 sensors to go bad. Perhaps bad fuel, too much heat produced from the cat can melt the cables, or they just go bad at some point.