PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Normal o2 mv range?

Thread Tools
 
Search this Thread
 
Old 10-09-2010 | 11:22 PM
  #1  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default Normal o2 mv range?

Can someone tell me what the normal mv range is for o2s please?
Old 10-10-2010 | 12:55 AM
  #2  
MontecarloDrag's Avatar
10 Second Club
iTrader: (3)
 
Joined: Aug 2005
Posts: 889
Likes: 5
Default

Usually from 0 mV to 1100 mV
0 mV= AFR 15 or higher
1100 mV=AFR 14 or lower
Old 10-10-2010 | 01:14 AM
  #3  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

its that wide of a range huh. Iv been reading 50mv to around 900mv but cant find a better answer. What range should I be looking for open loop vs closed?
Old 10-10-2010 | 01:24 AM
  #4  
MontecarloDrag's Avatar
10 Second Club
iTrader: (3)
 
Joined: Aug 2005
Posts: 889
Likes: 5
Default

Originally Posted by senicalj4579
its that wide of a range huh. Iv been reading 50mv to around 900mv but cant find a better answer. What range should I be looking for open loop vs closed?
No, it is a narrow band, only from 14 to 15 AFR.
Wideband goes from 0 to 5000 mV, from 8 to 22 AFR aprox.

Your readings are ok. All oxygen sensors should switch from low to high volts to work properly. Don't expect a fixed mV reading for a given AFR, narrow band O2 don't work that way. Even in closed loop you will see them go from almost 0 to 900, like a sinus wave.

In open loop depends on the actual AFR. Any AFR lower than 14 will output 900 mV aprox.
Any AFR leaner than 15 will output 0mV aprox.
Stoich is around 450mV
Old 10-10-2010 | 01:30 AM
  #5  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

Im gonna do some scanning within this week and get a closer number.
If I have the Insufficient Switching codes shouldnt the mv numbers be all screwy?
I also have slow response code.
Old 10-10-2010 | 01:50 AM
  #6  
MontecarloDrag's Avatar
10 Second Club
iTrader: (3)
 
Joined: Aug 2005
Posts: 889
Likes: 5
Default

Not screwy, but you will see less changes per minute from low to high volts.
O2 switch pretty fast on closed loop at idle.

Your O2 may be bad.
Old 10-10-2010 | 06:49 AM
  #7  
MUSTANGBRKR02's Avatar
12 Second Club
iTrader: (91)
 
Joined: Aug 2006
Posts: 4,599
Likes: 5
From: Maine
Default

Slow switching o2's look like a gradual hill vs peaks and valleys( normal switching)
Old 10-11-2010 | 12:35 PM
  #8  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

Ok,I use a aeroforce interceptor scan gauge.
Seonsor 1 bank 1 is reading 930mv-960mv when car is full operating temp and idle. It dose change when the fans come on though. Also I have seen roughly 50mv-950mv when car is started. I think thats normal correct?

Now sensor 1 bank 2 is a different story. Its reading 430mv-450mv and staying 440mv-450mv most of the time. What can you tell me about this?

Codes I have on the car are pretty much normal for headers...
p0140
p0160
p1133
p1153
p0133
Can someone school me a little on what I should be seeing o2 in mv?

Last edited by senicalj4579; 10-11-2010 at 01:04 PM.
Old 10-11-2010 | 01:22 PM
  #9  
THErobertH's Avatar
Teching In
 
Joined: Sep 2010
Posts: 43
Likes: 0
From: fresno
Default

Most accurate way to check is by using an oscilloscope, i.e. picoscope.
sine wave as stated above should be switching from lean to rich, lean rich, and so on.
Old 10-11-2010 | 01:52 PM
  #10  
jimmyblue's Avatar
Moderator
iTrader: (11)
 
Joined: Mar 2002
Posts: 12,604
Likes: 6
From: East Central Florida
Default

The max voltage depends more on temperature than
mixture. That's why WOT tuning by narrowbands is a
fool's game.
Old 10-11-2010 | 01:53 PM
  #11  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

I switched the 2 o2 locations. The mv #s stayed the same and didnt follow to the other sides. Also to make sure I did swap them I swaped them once again and still same result.
Old 10-11-2010 | 01:59 PM
  #12  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

Originally Posted by jimmyblue
The max voltage depends more on temperature than
mixture. That's why WOT tuning by narrowbands is a
fool's game.
Ok im lost. Why are they reading different #s on each side? The coolant temp is full operating temp. Pass side is pretty much hanging around 450mv while driver side is bouncing anywhere from 0-950mv.
Isnt this not right? Is there a problem? Im just getting into all this scanning and im overwelmed from ignorance.
Old 10-11-2010 | 02:03 PM
  #13  
bene's Avatar
Trunion King

iTrader: (16)
 
Joined: May 2006
Posts: 4,394
Likes: 3
From: Texan in Colorado
Default

Originally Posted by senicalj4579
I switched the 2 o2 locations. The mv #s stayed the same and didnt follow to the other sides. Also to make sure I did swap them I swaped them once again and still same result.
Check for leaks on the side w/ bank 2.
Old 10-11-2010 | 02:19 PM
  #14  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

Originally Posted by bene
Check for leaks on the side w/ bank 2.
Iv actualy done this a few times. If there is one then its so tiny that you cant hear or feel it. I plan on taking the headers+exhaust off the car and reinstalling this winter.
Old 10-11-2010 | 02:22 PM
  #15  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

I plan on going to the track on wed. Could you guys tell me if this is going to hurt my 1/4 time?
Old 10-11-2010 | 07:08 PM
  #16  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

cant be the o2 sensors because I swaped the o2s out side to side and the 450mv didnt follow to the other side. And It cant be extentions for the headers because I am using the bosch 13111 with longer leads.
What could be keeping bank2 from oscilating?

Last edited by senicalj4579; 10-11-2010 at 07:20 PM.
Old 10-11-2010 | 11:05 PM
  #17  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

Why would bank 1 be oscillating fine (50mv-950mv) but bank 2 is flatlined? (430mv-450mv)
Old 10-12-2010 | 12:30 AM
  #18  
jimmyblue's Avatar
Moderator
iTrader: (11)
 
Joined: Mar 2002
Posts: 12,604
Likes: 6
From: East Central Florida
Default

The PCM will pin the O2 sensor voltage if it faults it.
See any O2 sensor related codes for that bank?
Old 10-12-2010 | 12:54 AM
  #19  
senicalj4579's Avatar
Thread Starter
10 Second Club
15 Year Member
iTrader: (41)
 
Joined: Jan 2006
Posts: 5,259
Likes: 23
Default

Originally Posted by jimmyblue
The PCM will pin the O2 sensor voltage if it faults it.
See any O2 sensor related codes for that bank?
Well, I have...
p0140
p0160
p1133
p1153 = this is one for bank 2
p0133

Im thinking I need to test the wires. On bank 2. But I have codes for bank 1 and the o2 readings seem fine there.
Old 10-12-2010 | 03:52 PM
  #20  
THErobertH's Avatar
Teching In
 
Joined: Sep 2010
Posts: 43
Likes: 0
From: fresno
Default

and you're reading the voltage from the DLC, or from the sensor


Quick Reply: Normal o2 mv range?



All times are GMT -5. The time now is 04:10 PM.