Failing emissions running rich mystery

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anitarrc

Active Member
Posts
194
Location
Tilarán
Here is the problem, my disco keeps giving me a HIGH lambda after running for about 10 minutes and starts throwing out unburnt fuel.
I have changed so far
cats (not the ones running around here)
the upper 2 oxygen sensors , swapped with two that passed riteve (CT,MOT,TUV, Keuring) only 4 weeks ago.
Swapped IACV from the same other car.
MAF.

I still get the same errors in the following cases (MAF works prefectly, earth is good)
P1592 = ROUGH ROAD SIGNAL IMPLAUSIBLE DRIVE CYCLE A, WHICH HAS OCCURED ONCE
(SIGNAL INVALID, THE FAULT IS CURRENTLY PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT). P0102 = MASS AIR FLOW SENSOR FAULT DRIVE CYCLE A, WHICH HAS OCCURED ONCE
(SIGNAL TOO LOW, THE FAULT IS CURRENTLY PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT). P1000 = LAMBDA SENSOR UPSTREAM CATALYST BANK 2 DRIVE CYCLE C, WHICH HAS OCCURED ONCE
(SIGNAL MISSING, THE FAULT IS CURRENTLY NOT PRESENT, THIS FAULT DOES NOT GIVE MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT). P0141 = OXYGEN SENSOR HEATER DOWNSTREAM CATALYST BANK 1 DRIVE CYCLE C, WHICH HAS OCCURED ONCE
(SIGNAL TOO LOW, THE FAULT IS CURRENTLY PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT). P0161 = LAMBDA SENSOR HEATER DOWNSTREAM CATALYST BANK 2 DRIVE CYCLE C, WHICH HAS OCCURED ONCE
(SIGNAL TOO LOW, THE FAULT IS CURRENTLY NOT PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT). P1000 = UPSTREAM OXYGEN SENSORS CONNECTED INCORRECTLY (SWAPPED) DRIVE CYCLE C, WHICH HAS OCCURED ONCE
(SIGNAL INVALID, THE FAULT IS CURRENTLY PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT).
 

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If it is throwing out unburnt fuel it implies the Lambda AFTER the cat or cats may not be working and it does mention that,
"P0141 = OXYGEN SENSOR HEATER DOWNSTREAM CATALYST BANK 1 DRIVE CYCLE C, WHICH HAS OCCURED ONCE
(SIGNAL TOO LOW, THE FAULT IS CURRENTLY PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT).
P0161 = LAMBDA SENSOR HEATER DOWNSTREAM CATALYST BANK 2 DRIVE CYCLE C, WHICH HAS OCCURED ONCE
(SIGNAL TOO LOW, THE FAULT IS CURRENTLY NOT PRESENT, THIS FAULT CAUSES MIL LAMP ACTIVATION, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT). "
I know fu ck all about this really except that my wife's car had a similar fault and when the lambda sensor the other end of the cat, i.e. closer to atmosphere, was changed it was cured.
But the rest of it I know nothing about so I searched for you and came up with the following:
for P1592 https://www.obd-data.com/p1592.html
For P0102 MAF sensor, https://www.autoblog.com/2016/03/12...BmVWtU1NdZiY3M9D-hhNK7auYgD4UGA_oqFsYh3xNfAQm
For P0141, which is the one I had and sorted out by changing the Lambda sensor downstream of the cat https://www.yourmechanic.com/articl... is the OBD-II,2 oxygen sensor heater circuit.
For P0161 https://www.yourmechanic.com/articl...cuit-malfunction-bank-2-sensor-2-by-evan-clay
For P1000 https://autoservicecosts.com/obd2-codes/p1000/
or maybe better to go through a load of other sites to be found here. https://www.google.com/search?ei=bp...hUKEwj4v8qRh4LrAhVE6uAKHR0aB8kQ4dUDCAw&uact=5

So there you go. All can be found on the internet. Hope this helps you a bit. Do let us know how you get on, all the very best,
Stan
 
thank you s much for your time.
I will try to borrow a downstream sensor. Till now I always thought they are redundant because the other car doesn't have them.
P1592 is somming in the ABS but then we have rough roads here all the time so I don't really take that too serious.
the explanation for P0102 doesn't apply methinks because 2 sensors give me the same & the earth is good & the values change correctly when revving up or driving with BOTH MAFs.
As to p1000 I forgot to say that yes I did check the wiring, no there was surprisingly no real earth in the plugs and no left and right are not mixed up. as Blackbox is suggesting above.

Will be really glad about any advice. I have paid 3 revisits now and it starts being way to costly for my very limited income during these bad times (really bad here with restrictions)
 
thank you s much for your time.
I will try to borrow a downstream sensor. Till now I always thought they are redundant because the other car doesn't have them.
P1592 is somming in the ABS but then we have rough roads here all the time so I don't really take that too serious.
the explanation for P0102 doesn't apply methinks because 2 sensors give me the same & the earth is good & the values change correctly when revving up or driving with BOTH MAFs.
As to p1000 I forgot to say that yes I did check the wiring, no there was surprisingly no real earth in the plugs and no left and right are not mixed up. as Blackbox is suggesting above.

Will be really glad about any advice. I have paid 3 revisits now and it starts being way to costly for my very limited income during these bad times (really bad here with restrictions)
That is why I bought a Foxwell nt 520, for Landrover and Jaguar range. Have a look here here for the latest version. After about three checks in a garage, you've paid the same.
If you are skint I am a bit reluctant to offer advice unless as you say you can borrow bits to try out. But I'd start with the downstream lambda sensors.
Best of luck.
Stan
 
Dear Stanley I have a blackbox faultmate.. that is where the above stuff is from. It is the MAF error and why it starts running rich only after 10 minutes that I really don't understand.I have no choice, I need my car. And in 18 days I am leaving after 6 years to get a job in Portugal, so I have to get it sorted asap.
 
Dear Stanley I have a blackbox faultmate.. that is where the above stuff is from. It is the MAF error and why it starts running rich only after 10 minutes that I really don't understand.I have no choice, I need my car. And in 18 days I am leaving after 6 years to get a job in Portugal, so I have to get it sorted asap.
Sorry, from the "3 revisits" I thought you meant to get it diagnosed!:rolleyes:
I am assuming here you have a V8 petrol, so I don't know if this will work, but with a TD5, if you disconnect the MAF, the ECU senses it and puts it straight on a "get you home" which is almost indistinguishable from a normal drive. But Maf sensors can be really sh!t. I have paid lots of dosh for one and it has gone bad in no time.

Just checked you info and found a/ you are a lady! So I will watch my language and B/ you are an LR electrician, so I am sure you know tons more than me about all this.
But maybe just swapping MAFs for known good ones is a route to try? If the "disconnect" thing doesn't work on petrols.
Other mechanical things, like collapsing intake tubing etc, I suppose you have already looked into.
As it kicks in after 10 minutes could it be linked to a thermostat or a temp signal fault?
Reaching for straws a bit here!
Best of luck
Stan.
 
thank you, some answers between the lines
[QUOTE="Stanleysteamer, post: 4937462, member: 107273"
I am assuming here you have a V8 petrol, so I don't know if this will work, but with a TD5, if you disconnect the MAF, the ECU senses it and puts it straight on a "get you home" which is almost indistinguishable from a normal drive. But Maf sensors can be really sh!t. I have paid lots of dosh for one and it has gone bad in no time..[/QUOTE]
Actually, most td5s work ok with the MAF disconnected. At least manual Defs and Discos. that is more critivcal with the later, NNN ECUs
Just checked you info and found a/ you are a lady! So I will watch my language and B/ you are an LR electrician, so I am sure you know tons more than me about all this.
.

Nerver mind I am very used to some flowery language in various languages. I know the right name for the last stud on the manifold in at least 4 of them :D
BTW sometimes one doesn`t see what is right in front of one`s nose
.
But maybe just swapping MAFs for known good ones is a route to try? If the "disconnect" thing doesn't work on petrols.

Other mechanical things, like collapsing intake tubing etc, I suppose you have already looked into.
As it kicks in after 10 minutes could it be linked to a thermostat or a temp signal fault?

.
All are good ideas. Temp signa is fine. Checked tubes. Am wondeing whether my slightly disgusting silencer coud be obstructing.

here are more screenshots. Rich lambda as I start, good looking later but don`t like the signals from the downstream ones. the better one is the the RH upstream
Reaching for straws a bit here!
Best of luck
Stan.[/QUOTE]
a
 

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thank you, some answers between the lines
[QUOTE="Stanleysteamer, post: 4937462, member: 107273"
I am assuming here you have a V8 petrol, so I don't know if this will work, but with a TD5, if you disconnect the MAF, the ECU senses it and puts it straight on a "get you home" which is almost indistinguishable from a normal drive. But Maf sensors can be really sh!t. I have paid lots of dosh for one and it has gone bad in no time..
Actually, most td5s work ok with the MAF disconnected. At least manual Defs and Discos. that is more critivcal with the later, NNN ECUs


Nerver mind I am very used to some flowery language in various languages. I know the right name for the last stud on the manifold in at least 4 of them :D
BTW sometimes one doesn`t see what is right in front of one`s nose
.
All are good ideas. Temp signa is fine. Checked tubes. Am wondeing whether my slightly disgusting silencer coud be obstructing.

here are more screenshots. Rich lambda as I start, good looking later but don`t like the signals from the downstream ones. the better one is the the RH upstream
Reaching for straws a bit here!
Best of luck
Stan.[/QUOTE]
a[/QUOTE]
Collapsed baffles could be a problem, I once had an exhaust on a kit car, then changed it for the pukka, expensive, funny, bendy stainless one recommended, the tickover climbed up by nearly 1000 revs. Similar story on other cars, Maybe a temporary replacement with a bit of straight pipe and some big jubilee or other exhaust clamps, just to see?
Partially blocked cat? lambdas downstream reading fine until heated up on hot exhaust? Or simply downstream lambdas giving up the ghost? The one on wifey's car gave up at about 54k miles. The screenshots mean little to me as I am just too "not into electronics" but there are others on her who really are. Have you tried posting in the RR section? I'd do that as your very next move. People like @wammers know their stuff.
 
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