All 4 O2 Sensors Bad? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Taurus | Mercury Sable | Ford Taurus SHO | 1986-2007 Forum for discussion of the Ford Taurus, Mercury Sable and Ford Taurus SHO. Covers vehicle years: 1986-2007

 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 09-14-07, 09:15 PM Thread Starter
Registered User
 
Join Date: Sep 2007
Posts: 3
All 4 O2 Sensors Bad?

I recently took my 98' taurus (3.0) to have the codes pulled (due to a service engine soon light). The codes said that all 4 of my oxygen sensors are bad.

The light has only been on for 2 weeks and about 1 week ago, the light went out for one day. This seems a little odd, to have all 4 go out at exactly the same time. Is this an electrical problem, or is it actually the sensors? Any advice? Thanks.

pooperscooper is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 09-15-07, 07:13 AM
Registered User
 
tbird100636's Avatar
 
Join Date: Jan 2005
Location: Massachusetts
Age: 34
Posts: 1,835
Question Re: All 4 O2 Sensors Bad?

Quote:
Originally Posted by pooperscooper
I recently took my 98' taurus (3.0) to have the codes pulled (due to a service engine soon light). The codes said that all 4 of my oxygen sensors are bad.

The light has only been on for 2 weeks and about 1 week ago, the light went out for one day. This seems a little odd, to have all 4 go out at exactly the same time. Is this an electrical problem, or is it actually the sensors? Any advice? Thanks.
What were the exact codes???

Master ASE Certified L1 Chrysler Technician- still a Ford fan at heart.
1964 Thunderbird Hardtop- Chantily Beige- 390 FE 4V V8-Uncle's Car
1966 Thunderbird Convertible- Red- 390 FE 4V V8- Uncle's other car- waiting for paint and body work!!!
tbird100636 is offline  
post #3 of 7 (permalink) Old 09-15-07, 10:21 AM
NESHO SCT Tuner
 
Join Date: Mar 2003
Location: Illinois
Posts: 703
Re: All 4 O2 Sensors Bad?

I agree. There is either a wiring problem or a PCM problem.

If you can trace the wires down on the PCM connector you can back probe the connector and see what the O2s are sending back with a voltmeter. They should oscillate between ~.3 to ~.7 volts.
SHOZ123 is offline  
post #4 of 7 (permalink) Old 09-15-07, 01:05 PM Thread Starter
Registered User
 
Join Date: Sep 2007
Posts: 3
Re: All 4 O2 Sensors Bad?

Thanks SHOZ123. I was going to do the backprobing, but I didn't now what the parameters were. That will help.
pooperscooper is offline  
post #5 of 7 (permalink) Old 09-15-07, 01:57 PM
NESHO SCT Tuner
 
Join Date: Mar 2003
Location: Illinois
Posts: 703
Re: All 4 O2 Sensors Bad?

You should not see 0volts or higher than 1.5V
SHOZ123 is offline  
post #6 of 7 (permalink) Old 09-21-07, 01:15 PM Thread Starter
Registered User
 
Join Date: Sep 2007
Posts: 3
Re: All 4 O2 Sensors Bad?

Follow UP:

After debating on diagnosing my electrical issues, I realized that a professional would be better suited for the job. I found a guy in Fremont, CA that charged $80. His report found that it's actually a problem with the PCM. He's saying that, although the 02 sensors and heaters are good, the heaters aren't getting the proper signal. He then quoted me $650 to replace it.

I have searched ebay for used pcm's and they seem to be going for about $50. Does anyone know how difficult it is to replace? It seems to be lodged inside the firewall, but I don't want to just rip it out without any input from people with experience. Thanks.
pooperscooper is offline  
post #7 of 7 (permalink) Old 09-21-07, 05:56 PM
Registered User
 
RickMN's Avatar
 
Join Date: Jul 2007
Posts: 231
Re: All 4 O2 Sensors Bad?

Rather than go used, contact one of these places and have them rebuild yours. It will cost a bit more, but will have a warranty.

www.ecudirect.com
BBA reman. ABS, ecu's, throttle bodies, air mass meters, and catalytic converters
Fuel pumps - Leaf Springs - Fuel Injectors - Window motors

I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: http://www.ricksfreeautorepairadvice.com/
RickMN is offline  
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Cars and PAG Vehicles > Ford Taurus | Mercury Sable | Ford Taurus SHO | 1986-2007


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome