[matuva]

Hi all,

I'm still waiting my O² sensor simulator to cure a P0420 code.

This code appears every average 100 kms, so, at the moment I just erase the code and wait...
Till today... Now, the MIL lights on as soon as every 15~20 kms, but for a full set of DTCs:
- 1/9: P2187, generic - current - System too lean bank 1
- 2/9: P0171 , generic - pending - System too lean bank 1
- 3/9: P0172 , generic - pending - System too lean bank 2
- 4/9: P2187, generic - pending - System too lean at idle bank 1
- 5/9: P2188, generic - pending - System too rich at idle bank 1
- 6/9: P0174, generic - pending - System too lean bank 2
- 7/9: P0175, generic - pending - System too rich bank 2
- 8/9: P2189, generic - pending - System too lean at idle bank 2
- 9/9: P2190, generic - pending - System too rich at idle bank 2

I drove my Santa for several kilometers today. Each evey 15~20 kms, MIL goes ON, I stop, clear the codes, and each 15~20 kms, they are back, and always in the same order...

The santa starts fine, runs fine, good power, no black smoke, no roten egg smell at exhaust, idles and purr like a kitten.
Note that the P0420 now never shows again :surprise:
Does that ring a bell to some of you? I confess I'm a bit at lost :frown:

 

[AUTOSPARK]

System too rich and system too lean codes together are sometimes a symptom of a leaking fuel tank purge control valve.

The easiest way to know if that's what's causing your codes is to take a pair of long nosed vise grips and clamp the hose between the valve and the inlet manifold to block the flow of gas into the inlet. If that gets rid of the fuel trim related codes you might need to replace the valve.

 

[matuva]

System too rich and system too lean codes together are sometimes a symptom of a leaking fuel tank purge control valve.

The easiest way to know if that's what's causing your codes is to take a pair of long nosed vise grips and clamp the hose between the valve and the inlet manifold to block the flow of gas into the inlet. If that gets rid of the fuel trim related codes you might need to replace the valve.

Thank you for your input!

I will try that ASAP.

Thanks for sharing your knowledge :grin2:

 

[matuva]

I did not have the time to perform the test, clamping the hose.

The codes have disappeared all of a sudden, as fast as they have appeared...

I have ordered a fuel tank purge control valve, I will change it anyways...

 

[matuva]

Purge control valve changed ( a true PITA ), and all codes gone.

Thanks Autospark

An annoying ticking noise has gone too. I believe the purge valve was at the end of life...

 

[grcauto]

Hi all,

I'm still waiting my O² sensor simulator to cure a P0420 code.

It doesn't cure anything and is illegal and if you get caught with it on your vehicle you'll pay a lot more than a new cat would cost you. I believe the minimum fine for the first time is 1K

 

[matuva]

It doesn't cure anything and is illegal and if you get caught with it on your vehicle you'll pay a lot more than a new cat would cost you. I believe the minimum fine for the first time is 1K

Yah, I know, this just fool the ECM, it doesn't repair the worn CAT.

I understand your warning about a potential fine, though, in my country, such restrictions do not exist yet, you can decat your engine using simulators or with a reflash, this not allowed, but this is not forbidden either... Our laws just don't say anything about that.

 

[matuva]

Here we are again

With the simulator, P0420 never shows again... but suddenly, P2271 has shown now :rant2:

I have checked the simulator voltage (the simulator replaces the sensor #2 on Bank #1) and it delivers a nice pulse signal from 0.000v to 0.92v, so I believe it is doing it's job fine...

So, I'm pretty convinced my Santa is cursed: how comes the PCM throws a P2271 code - O² sensor signal stuck rich Bank1 sensor2 - as the simulator which replaces this sensor 2 on bank1 does fine ???:huh::blink:

 

[matuva]

I contacted the seller of the simulator.

Here was my question:

I understand this is a different code.

Though, as the O² sensor no more exists as it is replaced by your simulator, I wonder why the ECM throws this P2271 DTC. The simulator is supposed to "simulate" the sensor, this is why I thought there was something to adjust on it to get rid of this P2271 DTC.
P2271 means the "sensor" is stuck at 1V, isn't it? When the signal from the O2 sensor is detected by the PCM as being stuck Rich or biased Rich, this DTC is set, so the question is why (or how comes) the simulator sends such a signal to the ECM.



and his reply:
Hello,
It is easy to figure out. Check if the simulator deliver the ECU the 0..0.9V pulse signal. If so, the upstream sensor is the culprit that should be replaced or eliminated. When it comes to eliminating either sensor with an electronic device the DTC codes will guide you certainly no more because ECU is fooled. So in condensed manner scan the front sensor’s voltage at high revs and most likely it doesn’t work in its full range.

So, even though the DTC point to the sensor #2 on Bank#1, the culprit is sensor #1?

 

[AUTOSPARK]

So, even though the DTC point to the sensor #2 on Bank#1, the culprit is sensor #1?

To me that just sounds like he wants to sell you another simulator to fit in place of sensor #1 :laugh:

CM throws a P2271 code - O² sensor signal stuck rich Bank1 sensor2

I don't know how these O2 sensor simulators work but the code suggests the simulator output voltage is staying high even when the engine is on overrun. When the engine is on overrun the mixture should be fully lean, which should result in the output voltages from all 4 O2 sensor switching low.

Do you have a simulator on bank 2 as well?
If not use your scan tool data list to monitor the B1S2 & B2S2 voltages during test drive. The two voltages should normally pretty much follow each other, but I suspect your simulator output will be very different from the output of the real O2 sensor because it has no way of knowing what the actual O2 content of the exhaust gas is.


I think engine PCMs are getting too smart these days to be fooled by these dumb simulators. Of course, I'm maybe being unfair calling the simulator dumb because I have no idea how they work. But I'd be very surprised if it actually monitors the O2 content of the exhaust gas and uses some logic to adjust the output voltage. I think it's more likely that it just takes a blind guess about what the output voltage should be and is getting it wrong.

 

[matuva]

I don't know how these O2 sensor simulators work but the code suggests the simulator output voltage is staying high even when the engine is on overrun. When the engine is on overrun the mixture should be fully lean, which should result in the output voltages from all 4 O2 sensor switching low.

OK, things get more clear to me

Do you have a simulator on bank 2 as well?

No, only this one, the other 3 sensors are stock.

If not use your scan tool data list to monitor the B1S2 & B2S2 voltages during test drive. The two voltages should normally pretty much follow each other, but I suspect your simulator output will be very different from the output of the real O2 sensor because it has no way of knowing what the actual O2 content of the exhaust gas is.

Yup, that does make sense to me

To me that just sounds like he wants to sell you another simulator to fit in place of sensor #1 :laugh:
.

no way :closedeyes:

I think engine PCMs are getting too smart these days to be fooled by these dumb simulators. Of course, I'm maybe being unfair calling the simulator dumb because I have no idea how they work. But I'd be very surprised if it actually monitors the O2 content of the exhaust gas and uses some logic to adjust the output voltage. I think it's more likely that it just takes a blind guess about what the output voltage should be and is getting it wrong.

I agree with that too... Finally, it should worth the pennies to accept the proposal of a friend's mechanic : delete CATs and reflash the PCM... not a cheap option, but the best one probably...

 

[AUTOSPARK]

Just a thought....rather than use a dumb sensor simulator, why not try linking your B1S2 & B2S2 signal wires together.

As I said before the output from these two sensor is pretty much the same when everything is working properly so I don't imagine the PCM would complain too much if they were exactly the same. It would certainly be closer to what it is expecting to see than what a dumb simulator can provide.

And just to be clear when I say dumb sensor I just mean the sensor has no real control logic built in. I'm not implying your dumb for using it :smile:

 

[matuva]

Just a thought....rather than use a dumb sensor simulator, why not try linking your B1S2 & B2S2 signal wires together.

That is an interesting idea. Anybody has the wiring diagram of these sensors, so I can try to pair them?

 

[grcauto]

I think you'll run into problems tying the signal lines together. I'm not sure it'll hurt the PCM but never know unless you try. Let us know how it works.

 

[matuva]

I think I should not tie together the power and ground lines, but just the signal ones? What d'you think?
Hurting the PCM is my fear....

 

[grcauto]

Maybe if you cut the bad side and use the good side to feed both inputs to the PCM. I wouldn't tie the two together as you be combining the two voltages.

 

[AUTOSPARK]

I've never done this so you do it at your own risk, but I honestly don't see any danger of damaging the PCM. If I thought that was even a remote possibility I wouldn't have even suggested it. Linking the two sensor connectors isn't feeding anything into the PCM (voltage level wise) that it wouldn't normally get, so I don't see that it will do any harm. Whether the PCM is fooled by it or not is another matter but I reckon it's more likely to be fooled by linking the sensor inputs than by the dumb simulator.


O2 sensor diagram, but it doesn't specify what V6 engine it's for so I assume they are both the same (2.7 V6 & 3.5 V6).

 

[nitely]

I would not cross any wires. Does this simulators have wire connection? If yes, that's your culprit. You should just use those $5 dorman anti fouler on the downstream O2 sensors? Been using them for years with no issue whatsoever. Can you post a pic? Its possible you have a failing O2 sensor. Or you may have damaged it on installation? Those anti fouler are great '99 [email protected] its kept my P0420 out for good.

 

[matuva]

I've never done this so you do it at your own risk, but I honestly don't see any danger of damaging the PCM. If I thought that was even a remote possibility I wouldn't have even suggested it. Linking the two sensor connectors isn't feeding anything into the PCM (voltage level wise) that it wouldn't normally get, so I don't see that it will do any harm. Whether the PCM is fooled by it or not is another matter but I reckon it's more likely to be fooled by linking the sensor inputs than by the dumb simulator.


O2 sensor diagram, but it doesn't specify what V6 engine it's for so I assume they are both the same (2.7 V6 & 3.5 V6).

Got it! Thanks for the diagram.

So, I should tie together prongs # 1 and #2 of sensors B1/S2 and B2/S2 only? So as to get the signal? or #3" and #4 too?

Or at least; may I wire together #3 too?

 

[matuva]

I would not cross any wires. Does this simulators have wire connection? If yes, that's your culprit. You should just use those $5 dorman anti fouler on the downstream O2 sensors? Been using them for years with no issue whatsoever. Can you post a pic? Its possible you have a failing O2 sensor. Or you may have damaged it on installation? Those anti fouler are great '99 [email protected] its kept my P0420 out for good.

I have tried these foolers, but unfortunately, it was a no luck for me :frown: