O2 sensors

[1996fordexplorer]

Hello, I have searched the threads before making a new one but I still have some questions, I have a 1996 ford explorer and have codes 172 & 174, O2 sensors left and right BUT does that include the O2 sensors at before and after the CAT? or due they have their own code? I have replaced the EGR, EGR rail, TPS, EGR seloind, Cleaned the throttle bottle, clean and tested maf sensor, clean and tested temperture intake sensor, replace the DEPFA(?) sensor. I have replaced vacuum hoses. Everytime I chase a code and repair it another code appears ! )ah) I have reset the pcm and have used two seperate readers to double check everything. Any help would be great, O Also should I just replace the front two O2 sensors and the CAT sensors and then reset pcm and see if any other codes appear?

 

[Explorer '96]

Just buy everthing new for the engine, it is worth it.

 

[G-96XLT]

I had a 96. I think they have 3 total. I would just do the 2 easy ones and see if it still blows codes. My code and bad emissions was the DPFE, once I changed that I had major improvement. I never had to go as far as the o2

 

[1996fordexplorer]

Is there any tips or tiricks in replacing them?

 

[waskly]

lots of bp blaster! soak them for a little bit of time.

 

[96eb96]

Hello, I have searched the threads before making a new one but I still have some questions, I have a 1996 ford explorer and have codes 172 & 174, O2 sensors left and right BUT does that include the O2 sensors at before and after the CAT? or due they have their own code? I have replaced the EGR, EGR rail, TPS, EGR seloind, Cleaned the throttle bottle, clean and tested maf sensor,

Those codes don't always mean the sensors are bad. They mean the sensors are being pushed to their limits (usually being caused by something else). Just FYI - many change o2 sensors for those codes only to have them come right back. Its like replacing tires that wear on one side by getting new ones, but not an alignment.

Could be upper intake o-rings. Also, how did you verify the MAF sensor is working? Did you check the baro parameter?

 

[Explorer '96]

Those codes don't always mean the sensors are bad. They mean the sensors are being pushed to their limits (usually being caused by something else). Just FYI - many change o2 sensors for those codes only to have them come right back. Its like replacing tires that wear on one side by getting new ones, but not an alignment.

Could be upper intake o-rings. Also, how did you verify the MAF sensor is working? Did you check the baro parameter?

Well doesnt code 174 mean it is to lean or to rich? So what else would make an engine to lean or to rich?

 

[96eb96]

Well doesnt code 174 mean it is to lean or to rich? So what else would make an engine to lean or to rich?

Also, Don't bother with the after cat sensor unless its to pass emissions. It exists to check if your cat converters work.

air leaks, bad maf, or fuel filter could cause those lean codes.

Usually when you get those codes on both sides of the engine, it is unlikely that both sensors are failing, but not impossible.

Bad o2 sensors usually give codes p0133 or p0153, which is a slow response. And 90% of the time its only one side involved.

Its like an employee is reported for doing nothing - there could be two reasons - either he is really a slacker, or his manager is really giving him nothing to do. In either case the big boss sees him doing nothing. So if you fire the employee, and hire someone else, they will still be doing nothing, because his boss is causing the issue.

Read this:
http://www.aa1car.com/library/ford_lean_codes.htm

I'm not saying the o2 sensors are definately OK, I just don't want you to replace them and end up at square one.

 

[1996fordexplorer]

thank you, both code readers say "left bank" & "right bank" isn't that both

Oxygen sensors? I have replaced the EGR, EGR rail, TPS, EGR seloind, Cleaned

the throttle body, clean and tested maf sensor, clean and tested temperture

intake sensor, replace the DEPFA(?) sensor. I have replaced vacuum hoses.

 

[1996fordexplorer]

What is bp blaster? is available?

 

[96eb96]

thank you, both code readers say "left bank" & "right bank" isn't that both

Oxygen sensors? I have replaced the EGR, EGR rail, TPS, EGR seloind, Cleaned

the throttle body, clean and tested maf sensor, clean and tested temperture

intake sensor, replace the DEPFA(?) sensor. I have replaced vacuum hoses.

Yes, thats both. I know the o-rings on the intake harden and let air in. Sometimes it just sets a lean code with no other issue.

How did you test the maf sensor?

 

[waskly]

What is bp blaster? is available?

http://www.amazon.com/Blaster-16-PB-Penetrating-Catalyst-oz/dp/B000I2079E

 

[96eb96]

What is bp blaster? is available?

he meant pb blaster. you can get it at walmart or an auto store. It helps free up parts that are stuck together.

 

[1996fordexplorer]

The MAF sensor was voltage, I had followed the book on checking and replacing parts. Is there a way to check the o-rings before just changing them out?

 

[1996fordexplorer]

I think the only thing left on the emmision system sensors are the oxygen

sensors. (whew) I know that it can be something else causing the codes, but

I want to test it first before just replacing.