Couple questions, One about P0138, and another about these weird switches i found.

[yukima]

Well my engine light came on almost instantly after i had it sitting for a month over the Christmas holidays,unless it came on before i parked it, but i don't remember it, and its pretty hard to miss. Anyways, my code reader finally came in today so i pulled the code and got p0138 which indicates high voltage in my oxygen sensor.

After reading around a little i see that its probably my sensor in the catalytic converter thats shot, so i'm wondering how hard is it to replace this sensor? Is it practically impossible to get at it without a lift? I'm not too bad a mechanical "things"... as long as i can get at it, which isn't the case a lot of the time with cars..

I just bought this car not too long ago (its a 2007 mazda 3 sport I), so i didn't know where the ODBII port was, i was looking around under the dash, and i noticed these two loose switch's beside my hood open leaver, one is a left-right on, off switch and the other one is a little red button. Ive never seen this before so i have absolutely no idea what they are for, they look like some bomb arming device to me, hahaha. Ill post a picture so you guys can see what I'm talking about. I'm not sure if this is in all 3's but it doesn't look like it to me.


Here it is.

Thanks In advance everyone.
Yukima

 

[hat1018]

I can tell you without a doubt those switches are not "stock". I would get those traced out and eliminate them if possible. As for your ox sensor, IIRC it is accessable from a creeper.

 

[silla3]

the little red button is sometime used with aftermarket alarm's

 

[superdoughboy4]

The red button is for the secret NOS, and the switch is to purge your nitrous system.
























[Don't take that seriously. Rofl]

 

[yukima]

The red button is for the secret NOS, and the switch is to purge your nitrous system.
























[Don't take that seriously. Rofl]

lmao

 

[yukima]

I see that this error code says that it is my rear o2 sensor that is giving me problems. I'm not quite sure where "rear" is located in regards to the sensors..? where should i be looking, I'm quite clueless on where this sensor is actually located. Any tips on where i could look threw would be nice.


Also how critical is it to replace this part? I live in Montreal so the ground is wet and snowy so its not exactly the most ideal time to work on my car... If it doesn't really matter ill wait until summer comes around to replace it on my own, if not i guess ill take it to a garage..

Thanks
Yukima