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Dan, ASE Certified Technician
Category: Mercury
Satisfied Customers: 1085
Experience:  Dealer Auto Technician
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Well its a mazda tribute with a 3.0 v6, 20003, yes have

Customer Question

well its a mazda tribute with a 3.0 v6
JA: What year is your Tribute?
Customer: 20003
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes have changed both o2 sensors and still showing the in the fault codes
JA: Have you located all of the vehicle's oxygen sensors? Are the wires leading to and from each intact and in good shape?
Customer: yes they looked fine it also shows a po443 evap purge control valve circuit
JA: Anything else you think the mechanic should know?
Customer: before the fuel cap light came on but that was a week ago it is now off and does not show as a code
Submitted: 3 months ago.
Category: Mercury
Expert:  Dan replied 3 months ago.


If your purge valve is stuck open it could be affecting the o2 sensors. It will be a vacuum leak and cause a lean code p0171 and p0171. Do you know which code for the oxygen sensors were there?

A faulty purge valve could cause an evap leak which would set the light for the gas cap as well.

Please reply to this if you need more help and we can continue this conversation. If you are satisfied with my service, please rate at the top of the screen. Rating does not close out your question. Remember, sometimes it is difficult to completely diagnose your vehicle without being there, but I will try to give you the best answer I can. If I am not giving you 5 star service, please let me know what I missed.



ASE Master Technician

Customer: replied 3 months ago.
I have a PO 443 code evaporative mission system purge valve circuit . PO 135 o2 sensor heater circuit bank one sensor one code PO 141 o2 sensor heater circuit bank one sensor two code PO 155 o2 sensor heater circuit bank 2sensor 2 heater circuit bank to censor to code P016 I have also changed out both O2 sensors and yet they still show this code I am not showing a lean code just the following po443,po135,po141,po155,po161
Expert:  Dan replied 3 months ago.

Have you check the wiring closely especially near the exhaust? Sometime wires can get melted from the heat of the exhaust. Look at the engine harness carefully for signs of rodents. Sometimes mice will chew through the harness as well.

Customer: replied 3 months ago.
Best I could the wiring harness for both o2 sensors was fine. I have looked at the Sylinode that is close to the fuel tank. I checked for continuity . I did get an ohms reading but it was too high to get an actual "tone"from my meter. I did not check for voltage though. Also there is a silanode under the hood I checked that I did get a continuity tome from my meter but did not not get a voltage reading but wasn't sure if your supposed to be getting voltage to that one all the time. If that makes any sense ?
Expert:  Dan replied 3 months ago.

Clear those codes out, turn the key on without starting. Rescan. Which codes come back?

Customer: replied 3 months ago.
Cleared out the codes. Cycled the key off waited 3secs then turned key back on Did Not start no codes were found I did have a yellow waning light on scanner I think it that it indicates the emission readiness status/car has to be driven according to the scanner owners manual.
Expert:  Dan replied 3 months ago.

Start it up and let me know which codes come up.

Customer: replied 3 months ago.
Ok I actually drove it around the block. The same previous codes came up under pending codes but did not set the engine light on.
Expert:  Dan replied 3 months ago.

Does it have any running issues?

Customer: replied 3 months ago.
PO 443,po135,po141,po155,po161
Expert:  Dan replied 3 months ago.

It may take a few drive cycles to set the light

Customer: replied 3 months ago.
Runs fine sounds fine has power I don't feel any changes in that regard
Expert:  Dan replied 3 months ago.

Is your scan tool able to read live data?

Customer: replied 3 months ago.
It says it can.
Customer: replied 3 months ago.
Ok I finished a live data test
Expert:  Dan replied 3 months ago.

Live data is not really a test, can you see the heater circuit voltage of the o2 sensors with the scan tool?

Do you have a multi meter? Are you able to do some electrical tests with a wiring diagram?

Expert:  Dan replied 2 months ago.

Hello again Dan here,

I am contacting you because the post has not been closed or rated.

This question is coming up on 7 days which means it will close.

You have already paid to get this question answered, but you have not rated.

Let me help some more. Is there anything else I can help you with?

If I did not give you 5 star service, please let me know what I missed.

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