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Bad O2s sensors - what are the symptoms

  • Thread starter Thread starter Methodical
  • Start date Start date Dec 25, 2005

Methodical

15 Year Member
Dec 1, 2003
1,192
11
59
Clinton, MD
Dec 25, 2005
#1
  • Dec 25, 2005
  • #1
Without testing anything, what are the symptoms of bad O2 sensors?

Thanks
Al
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Dec 25, 2005
#2
  • Dec 25, 2005
  • #2
A code or reduction in milage.

Good luck.
 

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Dec 25, 2005
#3
  • Dec 25, 2005
  • #3
And no change in WOT performance, as the computer reads only the maf, and not the O2's.
 

95COBRA241

New Member
Sep 3, 2005
339
0
0
Delray Beach, FL
Dec 25, 2005
#4
  • Dec 25, 2005
  • #4
When mine went bad, the car would not rev smoothly. sounded like a miss and the car was running rich.
 

Methodical

15 Year Member
Dec 1, 2003
1,192
11
59
Clinton, MD
Dec 26, 2005
#5
  • Dec 26, 2005
  • #5
95COBRA241 said:
When mine went bad, the car would not rev smoothly. sounded like a miss and the car was running rich.
Click to expand...

That's what my car is doing. I also datalogged my car and noticed my Kamrfs and Lambes were not very active nor were the O2s. The lambes would be between 12-14 and suddenly dropped to 10.8. I suspect it would have gone lower but maybe the computer won't show it. The other strange thing is during the datalog (while idling) the rpms would drop to about 500 rpms. I just got these 02s about 2-3 months ago (Bosch). I will reinstall the factory O2s to see what happens. Hope it solves the problem. Will update.

Thanks
Al
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Dec 26, 2005
#6
  • Dec 26, 2005
  • #6
Al

In closed loop conditions, you should see them switching back & forth with much activity.

I could dig up a small flie where they were dlogged if you think it would help you

Grady
 

Methodical

15 Year Member
Dec 1, 2003
1,192
11
59
Clinton, MD
Dec 27, 2005
#7
  • Dec 27, 2005
  • #7
final5-0 said:
Al

In closed loop conditions, you should see them switching back & forth with much activity.

I could dig up a small flie where they were dlogged if you think it would help you

Grady
Click to expand...


Hey Grady. Yes I'd be interested in the dlog.

thanks
Al
 

final5-0

Mustang Master
Apr 6, 2003
6,817
12
79
DFW Texas
Dec 27, 2005
#8
  • Dec 27, 2005
  • #8
OK Al

I had to go back to March 03 to find a dlog with both HEGO 1 & 2

As I said above, as long as they are active and switching rapidly, everybody I have ever talked to about this subject seems to think that means they are good.

I've never paid much attention to them really and rarely dlog them. When I do, it is usually just one of them that I collect data from.

The file I got the shots from is around 1mb in size and has a total of about 1600 data events.

IIRC, you get about 10 samples per sec so maybe about 2.5 minutes give or take for length in time.

The conditions the file was taken from were:
Idle only
Normal ect's
Normal Open Loop idle conditions

I went ahead and included one shot of the raw data from the start of the file.
23 data events is all you can capture in one shot but I made sure you could see LAMBSE,KAMRF, & WB data along with both HEGO's.

Hopes this gives you an idea of what I was trying to get across about the HEGO's switching back & forth.




 

Methodical

15 Year Member
Dec 1, 2003
1,192
11
59
Clinton, MD
Dec 29, 2005
#9
  • Dec 29, 2005
  • #9
final5-0 said:
OK Al

I had to go back to March 03 to find a dlog with both HEGO 1 & 2

As I said above, as long as they are active and switching rapidly, everybody I have ever talked to about this subject seems to think that means they are good.

I've never paid much attention to them really and rarely dlog them. When I do, it is usually just one of them that I collect data from.

The file I got the shots from is around 1mb in size and has a total of about 1600 data events.

IIRC, you get about 10 samples per sec so maybe about 2.5 minutes give or take for length in time.

The conditions the file was taken from were:
Idle only
Normal ect's
Normal Open Loop idle conditions

I went ahead and included one shot of the raw data from the start of the file.
23 data events is all you can capture in one shot but I made sure you could see LAMBSE,KAMRF, & WB data along with both HEGO's.

Hopes this gives you an idea of what I was trying to get across about the HEGO's switching back & forth.




Click to expand...


Thanks Grady. Sorry for the delay in response. I've been doing demolition work in my kitchen. I don't have to return to work 'til 1/9. So I am tiling the kitchen. And plan to get some tune time in also.

Oh yeah, my O2s are lazy. I will reinstall the stock ones to see what happens.

Peace
Al
 
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