P0133 Heated Exhaust Oxygen Sensor

[richie9mt]

2006 4.0L V6 89K miles. Been running pretty well since 'fixing' my other problems. About 100 miles since then. Had this DTC (pic attached) pop up during a quick check to see if I still had P1000 DTC. (My manual tells me P1000 must be deleted to pass my state inspection).

The P0133 was unexpected. No dash warning light. I did a Search this forum; no threads. Searched the Web, found a couple about replacing the sensors. Checked Rock Auto, no Motorcraft (the recommended sensor, supposedly Bosch sensors are suspect) upstream sensors.

I'm sure a pair from Ford will cost over a hundred, so before I start throwing parts at the car (I know nothing about electronics), what should I know about this sensor problem? Is it an intermittent voltage reading that may go away? I've put 1,000 miles on the car since buying it used; no HO2 sensor problems before.

Any comments appreciated! Thank you for your time!

 

[GlassTop09]

2006 4.0L V6 89K miles. Been running pretty well since 'fixing' my other problems. About 100 miles since then. Had this DTC (pic attached) pop up during a quick check to see if I still had P1000 DTC. (My manual tells me P1000 must be deleted to pass my state inspection).

The P0133 was unexpected. No dash warning light. I did a Search this forum; no threads. Searched the Web, found a couple about replacing the sensors. Checked Rock Auto, no Motorcraft (the recommended sensor, supposedly Bosch sensors are suspect) upstream sensors.

I'm sure a pair from Ford will cost over a hundred, so before I start throwing parts at the car (I know nothing about electronics), what should I know about this sensor problem? Is it an intermittent voltage reading that may go away? I've put 1,000 miles on the car since buying it used; no HO2 sensor problems before.

Any comments appreciated! Thank you for your time!

View attachment 84403

Hi richie9mt,
You have the right software to check this. 1st, Forscan is telling you that the P0133 HO2S-11 DTC is pending--meaning it hasn't become permanent (the -P at end of DTC & in 2nd screen shot the "Status:") tis why no MIL is lit.......yet. The PCM has noted on occasion that HO2S-11's switching rate is starting to take too long to react to PCM's rich\lean switching commands (max time is 100 ms for HO2S to react from .800mV to .200mV & vise-versa......called V\ms transition rate.....the less time it takes to transition the better the HO2S is operating). Yes, this can be intermittent thus can be somewhat hard to track\catch.....but Forscan can help w\ this by setting up all 4 HO2S sensor's voltage PIDs in the Dashboard graphing.

1st thing though, click on the P0133-FF to look at the FF (freeze frame) data (PCM makes a copy of all the live data at the time it set the pending DTC for diagnostic purposes......should have captured these HO2S's voltage data & you should be able to pull that data up for review). Refer to Forscan FAQ for how to access. If can't find it, then continue below:

Set up HO2S11, then HO2S21, then HO2S12, then HO2S22 (might as well set up the 2 rear HO2S's that monitor the cats since you're in there........you'll be needing this in future.....good way to check cat operation) in column in 1st column of Dashboard from left (so Forscan can then graph the raw HO2S voltage signals data in Oscilloscope for comparison of both 11-21 HO2S's voltage output signals. BTW, Forscan can graph up to 12 PIDs in Oscilloscope....FYI). Since PCM hasn't flagged HO2S-21, its switching rate is deemed OK by PCM so you can compare HO2S-11's switch rate to HO2S-21 to see if HO2S-11 is indeed switching slower to verify the DTC.

Then drive car with Forscan hooked up & recording in Dashboard, then check to see if you can see the HO2S-11 switch rate get slower than HO2S-21. Then take it from there.

The most usual cause is an aging HO2S, but other issues can aggravate this (like excessive EVAP rich\lean from leaking CPV or small vacuum leak or EGR leak, HO2S contamination from oil\coolant, etc) so get ready to consider other possibilities while you're at it as whatever it is, it's in the early stages of eventual failure thus intermittent so may be hard to pin down. The data is suggesting that the cause is isolated to B1, but this can be deceiving as B2 may be just at the threshold of setting the same P0153 DTC so both sensors may draw very similar patterns visually.....only B1S1 crossed the threshold for now at least on 1 occasion so PCM only shows the P0133 pending DTC. Keep this in mind while diagnosing your issue.

Sometimes the best way to find the actual cause w\ modern computer-controlled powertrain systems is verifying everything else is NOT the cause thus eliminate them from the potential cause list, so can take some time\effort to close in on it.

Hope this helps.

PS edit--Almost forgot........Ford now is using BOSCH 51717 NB HO2S as OEM replacement's (FoMoCo F85F-9G444-BD) for these 05-10 S197's nowadays so be aware. The HO2S's that match these early S197's are NTK 22060 (front), NTK 22500 (rear) NB HO2S. The issue w\ the Bosch's is the voltage output signal specs are different & the NTK's were the Ford OEM sensors when these cars were manufactured thus the PCM is tuned for the NTK output voltage specs. The Bosch's can work w\ these cars (Ford listed them as compatible), but they can also cause some erratic operation if the PCM isn't retuned to accept their signal outputs (mainly the heater circuits as the Bosch's heaters aren't as strong as the NTK's thus take too long to heat up & maintain sufficient operating temps). FYI.

 

[richie9mt]

You have the right software to check this...Refer to Forscan FAQ for how to access. If can't find it, then continue below:...

Thanks for your comments! So far, ForScan has been way above my head. I'll check the FAQ again and try to muddle thru whatever it all is...

Edit: I must have the wrong FAQ...

https://forscan.org/faq.html

 

[GlassTop09]

Thanks for your comments! So far, ForScan has been way above my head. I'll check the FAQ again and try to muddle thru whatever it all is...

Edit: I must have the wrong FAQ...

https://forscan.org/faq.html

Ok, then go to HowTo section here:
Common principles of diagnostic with FORScan - FORScan forum

 

[richie9mt]

Ok, then go to HowTo section here:
Common principles of diagnostic with FORScan - FORScan forum

I appreciate your effort to help, but the 'documentation' for v2.3.48 is little and assumes too much. I did find a 'Documentation on Version 1.3.x' and printed it out. I'll try to get into it this week.

I've joined the Forscan Forum and it's pretty vague as well. Explanations of terms, how to navigate the various screens, and the functions of the displays are not self-evident. Forscan is still helpful in displaying the DTC's and where to look for the 'bad' part, but not how to test it. I assume the information is there, but it's not clear how to find it.

This particular DTC, P0133, seems clearly an O2 sensor impending failure. Thanks to your help, I now know what the "P" on the code stands for. I'll end up replacing both upstream sensors and go from there.

 

[Juice]

P is for powertrain, not pending.
The free test I would do is swap the two sensors and see if the code moves to the other bank. If it does, you confirmed you need to replace the one sensor.

 

[TomL]

I agree with the use of the NTK sensors. I recently replaced all 4, just for preventive maintenance reasons on my 05 and have no problems with them. I paid about $100 for all 4 from Rockauto. Also, I think they are made in the USA.

 

[richie9mt]

P is for powertrain, not pending.

Now you got me confused [again]. Isn't the P in front of the number for Powertrain???

Anyway, I agree with juice and TomL. I was all ready to order the O2 sensor(s) but I drove the Mustang out to Harbor Freight yesterday and bought that little O2 sensor 3/8" drive split-socket, about $8 IIRC. About 10-12 miles. This morning, I decided to delete the DTC for the B1S1 sensor but when Forscan read the DTC's...The DTC's were gone. Only code left was the always-present (it seems) P1000-FF right up at the top.

So now I'm bewildered as well as confused. An intermittant code? I didn't delete it, I'm "assuming" the PCM did.

Now what??? Go ahead and buy the sensor(s)? Wait for more DTC's? Pray it doesn't break down on the Thruway???

 

[Juice]

P is always for Powertrain code. There are three sections of codes:current, pending, and permanent.
Current codes are just that, fault exists now. CEL is ON.
Pending codes: soon to mature to current or disappear. Once current, it is stored in permanent codes. Permanent codes cannot be cleared. Must fix, than pcm will clear permanent codes. CEL is OFF for pending and permanent codes, as long as there are no current codes.

You cleared the code before itmatured and stored in permanent codes. That is why they are gone.
Just keep driving car as is, or swap O2s from side to side and keep driving. See what codes if any return.

 

[richie9mt]

Hi richie9mt,
You have the right software to check this.

GlassTop- Thank you for your response. I've been trying to make sense out of FORScan 2.3.48 with no luck. So, I loaded FORScan 1.3.9 on a spare HDD and scanned my Mustang with that. What a difference! I was actually able to see how those values you pointed out can be loaded into the dashboard for analysis/comparison. 2.3.48's Dashboard was already loaded with values/items (I don't know what else to call them) and I couldn't delete or reset the Dashboard to 'all boxes empty' so i could load in what i wanted. I can't even move the slider to see if the O2 sensor information is there. The FORScan Forum is not much help, as there is still no 'How To'.

I'm still plowing through the 1.3.9 'Tutorial' trying to figure out what they're talking about, but I'm getting further along. Still no idea when or if I should be starting/driving the car to get the values, but I'm hoping.

I appreciate your taking the time to write out that mini-tutorial on the O2 sensor issue. Thank you for your help!

Oh, yes - I did print out your post, and also printed out the items listed in my Dashboard for my car - all 261 of them! 10 screenshot/pages worth (I couldn't find a Print option). I think I found the O2 item names on page 6. I have no idea what they're called. I can't even find definitions for half the things in FORScan.

Thanks again for hrlping an old fart out with the new wave of diagnostics!

 

[GlassTop09]

GlassTop- Thank you for your response. I've been trying to make sense out of FORScan 2.3.48 with no luck. So, I loaded FORScan 1.3.9 on a spare HDD and scanned my Mustang with that. What a difference! I was actually able to see how those values you pointed out can be loaded into the dashboard for analysis/comparison. 2.3.48's Dashboard was already loaded with values/items (I don't know what else to call them) and I couldn't delete or reset the Dashboard to 'all boxes empty' so i could load in what i wanted. I can't even move the slider to see if the O2 sensor information is there. The FORScan Forum is not much help, as there is still no 'How To'.

I'm still plowing through the 1.3.9 'Tutorial' trying to figure out what they're talking about, but I'm getting further along. Still no idea when or if I should be starting/driving the car to get the values, but I'm hoping.

I appreciate your taking the time to write out that mini-tutorial on the O2 sensor issue. Thank you for your help!

Oh, yes - I did print out your post, and also printed out the items listed in my Dashboard for my car - all 261 of them! 10 screenshot/pages worth (I couldn't find a Print option). I think I found the O2 item names on page 6. I have no idea what they're called. I can't even find definitions for half the things in FORScan.

Thanks again for hrlping an old fart out with the new wave of diagnostics!

FWIW, the authors of Forscan don't go thru meticulous definitions of things as they assume that folks who use this software already have a certain base knowledge level of computer-controlled automotive diagnostic understanding so that they don't have to write\provide those kinds of instructions (can take a LOT of time\effort trying to explain computer-controlled automotive diagnostic jargon\process in layman's terms\meanings......some of this can't really be explained to such depths & make sense of it at the same time thus unfortunately there will be somewhat of a learning curve needed to try to meet the Forscan authors "in the middle" so to speak).

What can help you the most in using Forscan is actually learning the very Spanish Oaks PCM operations that your car is operating off of..........it is what Forscan is reading\pulling data out of.

Use this link (as you go along at your own pace) to access this Description & Operation section of the online copy of the Ford Workshop Manual to help you to get a better handle of what's actually going on at the PCM level to then translate to Forscan:
Ford Workshop Service & Repair Manuals - fordrepair.info - 2005 Mustang Powertrain Control And Emissions Diagnosis Section 1 description and operation (iihs.net)

There is a section on HO2S operation. This manual was written by Ford for their dealership service techs\mechanics to use to assist them w\ diag\TS & repair of these cars........

1 piece of advice I'd recommend for anyone who buys\acquires 1 of these S197's........at best these are older cars that are well past their warranties.......so to minimize a lot of head scratching & rabbit hole chasing you should get the car fully smoke leak tested when car is completely cold as soon as you can, 1st on the induction (intake) side, then 2nd the exhaust (mainly from the engine exhaust manifolds to end of midpipe to cover the HO2S's) side then 3rd the EVAP system (from CPV thru to the end of the EVAP vent line) to verify that all components\connections\air, fuel or vacuum lines\hoses are air tight\sound (you can get\make the unit & do it yourself or have someone who has access to 1 to do it.....money well spent over the long run) & if ANY leaks are found to fix\repair up front.....
Doing this will go a long way to eliminate a lot of potential drivability issues down the road as well as the easiest, fastest method to check\cover as much of the various powertrain systems in the least amount of time as very few of these cars over the years are\were kept up\checked as meticulous as they need to be IMHO......if we're being honest about it. This will also make the car much easier to diagnose\repair going forward as after doing this & verifying\repairing so all is known good, only electrically caused\induced issues will be left which the PCM is very good at ID'ing as it checks all electrical circuits that attach to it for integrity on every startup & continuously afterwards........not as good on pinpointing causes from potential drivability issues (like your P0133 pending DTC that you saw thru using Forscan, the PCM itself clear after it ran another system self-check on the HO2S's which the PCM does on every drive cycle....just as easily it can come back, depending on the circumstances that are causing the HO2S to switch slow) as there are several other variables that can cause the HO2S's (input signals) to switch slow that are not related to the HO2S's themselves.....but can affect their operations. Of course, you can always take the most common cause route & buy the HO2S's & install them........but then what you gonna do afterwards when the PCM relights the same DTC you tried to fix w\ the new parts?

I speak this from 1st hand knowledge\experience dealing w\ my own '09 GT Glass Top that I bought in 2017 w\ 139,438 mi on her. Typed a thread in the Chit Chat section covering all of this in a fair amount of detail over the years.

IMHO, put the effort in to learn how to use Forscan w\ your Stang.........it can save you a LOT of time & money on diagnostics\repairs\repeats thus is worth the time\effort to learn the software & how to use it.

Hope this helps.

 

[richie9mt]

FWIW, the authors of Forscan don't go thru meticulous definitions of things as they assume that folks who use this software already have a certain base knowledge level of computer-controlled automotive diagnostic(s)...

My level of understanding is minimal but I'm straining to come up to speed...It's a tough struggle...

FORScan just upgraded to v 2.3.49. I'm not sure how to install it (uninstall 2.3.48 & install 2.3.49 as 'new' install or just let the new version overwrite 2.3.48?) but I'm wondering if anything for my particular vehicle will change...

Having the dashboard empty would help. Maybe I should just hold off on upgrading, and hold my head next to a powerful magnet and hope a mental reboot will help my understanding...

 

[GlassTop09]

My level of understanding is minimal but I'm straining to come up to speed...It's a tough struggle...

FORScan just upgraded to v 2.3.49. I'm not sure how to install it (uninstall 2.3.48 & install 2.3.49 as 'new' install or just let the new version overwrite 2.3.48?) but I'm wondering if anything for my particular vehicle will change...

Having the dashboard empty would help. Maybe I should just hold off on upgrading, and hold my head next to a powerful magnet and hope a mental reboot will help my understanding...

FYI........................

I've always just downloaded the Forscan update file, open it & run it so it writes over itself (all saved logs, files, profiles & data is saved into a separate folder outside of the folder where Windows created for Forscan to run from that Forscan tells Windows to create in the Windows Documents folder so none of it is lost).

Just did this again w\ new vers 2.3.49 overwriting my last vers 2.3.41........all ran like clockwork & all comes back up normally & I can still access all my saved logs, profiles, data, etc so no issues.

Really don't know what else to say here............

Hope this helps.

 

[Juice]

Personally, I'm using an earlier version of Forscan.Last time I updated, I lost access to the VID block in the newer version. (I use this feature to adjust tire sizes and gear ratio. Faster and safer than a reflash just to adjust speedo calibration). If the new version has no new features for YOUR car, no point in updating the software.