Hi all,

Does anyone know the regular range of a working O2 sensor? My SES goes on randomly regarding Sensor 1 Bank 1 (which I guess is the one closes to the radiator), but the readings I get through the OBD2 scanner are a bit confusing.

Specifically, it shows one of the sensors to be at 1.27 Volts under acceleration, 2nd one being at about 70 mV and the third one at 800 mV. I am guessing the third one is the rear one and the 2nd one being the defective one... but I want some feedback from those who may know - thanks

 

Your logic seems pretty sound. I understand the normal range is between .1 and .9 volts, and that 72 millivolts (.072 volts) reading is well below normal range...

if that's even what you were asking...

 

Pretty much yeah that's what I asked.

I wonder why the other o2 sensor is jumping to 1.27 volts tho...

 

Another faulty sensor perhaps? A higher voltage reading could also be from too much fuel and not enough air, but that's (obviously) not concurrent with your other two readings... What were the Trouble codes you pulled?

 

O2 sensor should range from 1 volt down to 0 volts. Replace it. It should optimize your mileage too.

 

high voltage. its probably faulty. is one of the codes u got "o2 high voltage"?

as for what jwaxmax99 said about the gas mileage...it will go up, but nothing too noticable.

 

0509 - sensor 1 bank 1; but now i am confused as hell which one it is exactly - the one close to the radiator or to the firewall?

 

Bump - anyone can confirm this plz?

 

o2's are generally 1.5v pretty much near that +/- when in closed looped.

 

no no i mean sensor 1 bank 1 - is it the radiator one or the firewall one?

Thanks

 

Bank 1 = right side = firewall side.

 

Wait....can you confirm which code you pulled? 99's don't have regular codes like 95-98. They only have the ones that start with P since you can't check them manually. Which P code did you get?

 

0509 is the code I pulled.

 

I don't see 0509 listed as a DTC in the 1999 FSM.

 

http://forums.maxima.org/showthread....highlight=0509

The only thing is - this is for a 98; what about 99?!

Side 1 Bank 1 - which freakin side is this?!

 

Like i said, 99's don't have those type of codes where you count the times the CEL blinks since you can't check the codes manually. The 0509 doesn't apply to you. 99's only have Pxxxx codes (the ones you check through the OBD-II port) and according to the 1999 FSM P0509 doesn't exist.

 

Uhhhh yes it does; the SES blinked 0509 and my scantool recorded a P-somethign code that referenced to bank 1 sensor 1 (i reset the SES since then and it will come again - i'll scan using the obd scantool again).

But trust me - the 0509 code exists and does reference to the O2 sensor.



I jsut need someone to tell me which damn sensor it is on a 99 max - firewall or radiator side?!

 

The P-code was probably P0130.

Anyhow....
Taken from a few posts up.......

 

thanks!