How JustAnswer Works:

 
 
 
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
 
 
 
Ask Dan Your Own Question
Dan, Technician
Category: Cadillac
Positive Feedback: 95.7 %
Satisfied Customers: 18868
Experience: Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
Type Your Cadillac Question Here...
Dan is online now
A new question is answered every 9 seconds

2003 Cadillac: I replace the O2 sensor..CTS...error codes

Resolved Question:

I replace the O2 sensor in my 2003 Cadillac CTS. I am still getting 2 error codes, P0161 and P0160. Why will these not go away?

Submitted: 4 years ago.
Category: Cadillac
Picture
Expert:  Dan replied 4 years ago.

Check the PRE HO2S and POST HO2S fuses located in the under hood fuse block with the key on to verify they have power and fuses are in good. If they are good at this point you need to do a resistance test between the sensor and pcm on each of the wires. It could be a bad connector, if wires test out ok replace pcm. Let me know if you have questions. Thanks

 

 

P0161 Heated Oxygen Sensor (Bank 2 Sensor 2) Heater Circuit Malfunction

Possible CausesSetting Conditions
  • HO2S heater high side driver circuit has high resistance (open)
  • HO2S heater low side driver circuit has high resistance (open)
  • HO2S heater Ignition circuit is open (check the POST O2 fuse in fuse block)
  • HO2S heater element has failed
  • ECM has failed

P0160 Heated Oxygen Sensor (Bank 2 Sensor 2) Insufficient Activity

Possible CausesSetting Conditions
  • Check for air leaks in the exhaust manifold and in the exhaust pipes
  • Check for a restriction somewhere in the Exhaust system
  • HO2S air reference hole plugged (check for dirt on the outside)
  • HO2S signal circuit is open, or the low reference circuit is open
  • HO2S has failed (it may be contaminated with fuel, silicone or water)
  • ECM has failed

 

graphic

Dan40030.9900134259

Ask Your Own Cadillac Question
Customer: replied 4 years ago.

I checked the fuses and they are fine. I will have somebody who knows how to run the restiance test on the pcm do that.

Expert:  Dan replied 4 years ago.

Alright and when you do the resistance test between the sensor and pcm this will verify what the problem is. Let me know if you have questions you can respond to this answer at anytime even after you accept. Thanks

Dan, Technician
Category: Cadillac
Positive Feedback: 95.7 %
Satisfied Customers: 18868
Experience: Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
Dan and other Cadillac Specialists are ready to help you
Ask Your Own Question Now
Customer: replied 4 years ago.

OK We took the sensor from the drivers side and put it in the passenger side and the P0161, and P0160 codes went away so it isnt in the wiring or communication. Then we put the new sensor in the driver side and got the same codes for that side, P0141, P0140. We assumed that this meant that the sensor was bad so we exchanged it for another new one, same codes. Is there something special that a GM technician has to do to reset this code or what? Why won't they go away!

Picture
Expert:  Dan replied 4 years ago.

At this point you need to do a resistance test between the oxygen sensor and the pcm to verify the cirucit is good if so replace pcm. Let me know if you have questions, thanks.

Ask Your Own Cadillac Question
Customer: replied 4 years ago.

How could it be the PCM if the other codes went away when we hooked up the old sensor to the passenger side? The codes switch according to where we put the new sensor... Is it possible that the sensor has to be programed or something before it is installed? How expensive is a new PCM and wouldn't there be more problems if it was the PCM not just the O2 codes?

Picture
Expert:  Dan replied 4 years ago.

It is possible the pcm could be the problem and only be throwing those two codes. It does not have to be programmed. You can get a used pcm from www.car-parts.com to save money. If the new sensor sets a code for whatever side you put it in this makes me think it is a sensor problem. Do a resistance test on both new and old sensor to see if resistances are the same. If so you will need to do a resistance test on the oxygen sensor circuit. Thanks

Ask Your Own Cadillac Question

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
< Last | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Dave Nova's Avatar

    Dave Nova

    Cadillac Technician

    Positive Feedback:

    97.8 %

    Satisfied Customers:

    1432
    ASE Master Certification. GM World Class Certification
< Last | Next >
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Cadillac Technician

    Positive Feedback:

    97.8 %

    Satisfied Customers:

    1432
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/JF/JFN1/2011-2-26_33039_180754101501129867381533152761315265045893127711n.64x64.jpg Jerry Newton's Avatar

    Jerry Newton

    Cadillac Technician

    Positive Feedback:

    96.4 %

    Satisfied Customers:

    1127
    ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.
  • http://ww2.justanswer.com/uploads/PE/peterpete190/2012-2-24_1274_20120215135406.64x64.jpg Pete's Avatar

    Pete

    Cadillac Technician

    Positive Feedback:

    99.4 %

    Satisfied Customers:

    1028
    15 years Cadillac experience as a technician.
  • http://ww2.justanswer.com/uploads/tracker40/2010-02-26_211144_ja_picture.jpg Randall's Avatar

    Randall

    ASE Master Tech

    Positive Feedback:

    98.1 %

    Satisfied Customers:

    948
    ASE Master Tech, 32 years exp,Cadillac 6 yrs
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg john's Avatar

    john

    ASE Certified Technician

    Positive Feedback:

    100.0 %

    Satisfied Customers:

    941
    ASE CERTIFICATIONS A1-A8 & L1 / 40 YEARS AUTOMOTIVE EXPERIENCE
  • http://ww2.justanswer.com/uploads/fixitman/2008-10-13_161055_n1411944891_2367.jpg FIXITMAN's Avatar

    FIXITMAN

    Master Technician

    Positive Feedback:

    93.8 %

    Satisfied Customers:

    572
    ASE MASTER CERTIFIED, AA DEGREE AUTO/DIESEL TECH.
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H's Avatar

    George H

    ASE Certified Technician

    Positive Feedback:

    100.0 %

    Satisfied Customers:

    536
    ASE Master Tech 15+ Years