2003 Land Rover Discovery SE 92k miles Check Engine Light

[umoms]

I just recently bought a 2003 Land Rover Discovery with 92k miles and check Engine light came on. I pulled the following codes.

P0130
P0171
P1171

Any suggestions ?

 

[Disco Squared]

P0130--O2 sensor malfunction (bank 1, sensor 1)
P0171--System to rich (bank 1) multiplicative injector adapting
P1171--System too rich (bank1) additive injector adapting

Any suggestions ? you've got one or more cylinders not burning the fuel completely and causing a "too rich" malfunction.
IMHO--It could be dirty fuel injectors not atomizing the fuel properly. You could try a quality bottle of fuel injection cleaner like BG-44 to see if it fixes the problem.

 

[Chongo]

codes

2003 Land Rover Discovery SE 92k miles Check Engine Light

I just recently bought a 2003 Land Rover Discovery with 92k miles and check Engine light came on. I pulled the following codes.

P0130
P0171
P1171

Any suggestions ?




PO130 : front sensor LH bank stoichiometric ratio outside operating band
( NAS only ) 02 circuit malfunction.

There are 4 systems parameters in the processors, depending on the environmental area the vehicle was destined for.

NAS This one is usually USA

NAS low emission This one is usually USA

UK/Europe/Japan/Australia

ROW/GOLF

What PO130 means in simple terms is that the oxygen sensor has produced a voltage, ( either lower or higher, or inconsistent ), than the design perameters of the sensor itself. The oxygen sensor works between .01 volts and 1 volt, and when outside of this range is usually the result of a faulty 02 sensor or wiring leading to it. This trouble code PO130 does not specify whether rich or lean, it simply states that there is something wrong in the circuitry inside or leading to the sensor. There’s a strong chance the 02 sensor is bad, but it could be electrical wiring as well, or a combination of the two. Also what causes this code is a blown fuse under the hood which supplies the current to pre heats the heated O2 sensor, ( HO2S ). This will also place the vehicle in an open loop running mode.


PO171 : Multiplication injector adaptive fueling - rich limit exceeded LH bank

What this means, ( you got to love the over technical British wording here ), is that on the drivers side of the engine all 4 injectors allow too much fuel for the emissions operating parameters on acceleration. In instances the processor can cause this issue tying it in to another problem. This code, Po171 supports the PO130 code but adds a few other items that could be wrong in the mix. For example: 4 bad injectors, faulty processor, and wiring to name a few.
This code PO171 states the whole bank is too rich. I can see one injector going bad, but 4 at one time give me a break! Statistically speaking the probability of all 4 injectors going bad at one time is unheard of. It has to be something controlling all four on the drivers bank that is the issue. Faulty 02 and maf
sensors do this if they send the wrong info to the processor.


PO1171 : additive injector adaptive fueling - rich limit exceeded LH bank.

This is somewhat a redundant code of PO171 with the
exception of
one being additive in nature and the other being Multiplicative in
nature. This code here somewhat eliminates the theory of a bad
processor in your case since it supports Code PO171.



Additive: This is the processor
changing fuel demands through an additive
Strategy Analysis for optimized running per set parameters.
Prior data is being compared to current data and set parameters,
and re – calibrated to fit the new parameters. This is used in a
closed loop condition. If outside of these parameters, it sets
the code PO 1171.


Multiplicative: Is were the processor
applies fuel needs by a multiple of live
data and acquired data. A multiplicative strategy basically.
I believe this is used in open and closed loops, and also uses
additive analysis.


Now you know what it means, what do you do ?

Oddly enough 171 and 1171 are related to air
mixture control. Cleaning the maf sensor is the best way to start
here, and replace the air filter.

With the 130 code, You’ll most likely need to replace the HO2S
which is the oxygen sensor, but before you do that please check
all fuses under the hood and wiring beneath the vehicle as best
you can..

http://www.landroverworld.org/forums/showthread.php?t=11828


At this point there are a few important questions.

1: Are you adding any oil between oil changes ? Oil consumption ?

2: is the vehicle missing ? in any way ?

3: how is the air filter ?

4: any recent work done ?

5: last tune up ?

6: is there anything else that may have contributed to the issues ?



Good luck……….. Let us know………. Chongo

 

[umoms]

thanks for the thorough replies.

Honestly I only had this car for a short while so I haven't done anything to it. The air filter looks fairly new.

I have been told not to clean the MAF sensor as it could damage it. Is this true?

If not what can I use to clean it.

Also I am trying to just change what I need to for now so do you think its safe just to change the front drivers side O2 as thats the one that looks to be the culprit?


I am gonna also try some new gas and fuel injector cleaner and see if that helps.

 

[Chongo]

02

thanks for the thorough replies.

Honestly I only had this car for a short while so I haven't done anything to it. The air filter looks fairly new.

I have been told not to clean the MAF sensor as it could damage it. Is this true?

If not what can I use to clean it.

Also I am trying to just change what I need to for now so do you think its safe just to change the front drivers side O2 as thats the one that looks to be the culprit?


I am gonna also try some new gas and fuel injector cleaner and see if that helps.



To clean the maf sensor all you need is a fast evaporating solvent like lacquer thinner or m.e.k. or something similar. They offer it in spray cans, I use to use brakekleen but the changed the product almost ten years ago here in cali. The parts store you go to should be able to know of a product they sell for this task. The 02 could be the culprit. Not being there no one can be 100% sure, but it is a good step in the elimination process. It could be electrical issues. But the 130 code is most likely a 02 sensor. Check the fuses and the connectors before buying a new one.


Good luck…….. chongo

 

[umoms]

what fuses are you referring to? Is there a particular one?

 

[Chongo]

Fuses

what fuses are you referring to? Is there a particular one?



Sorry, I had to go to the market and get dinner stuff, My wife and I both have a cold right now, and I don't know who gave it to who.................. The fuses I'm refferring to are under the hood. Just to be safe, check them all. I've fixed a few rovers in my past by just wiggling the fuse, and it works. the contacts somtimes get some light corrosion between the fuse blades and connectors.

good luck.......... Chongo...........

 

[rioclimb]

I'm getting the same codes on my Discovery II

P0130
P0171
P01171

umoms,
Was the problem solved in your Land Rover?
What did you end up doing?

 

[NYNOLE]

I am getting the same codes, as well as p0139 (o2 sensor slow response, bank 1, sensor 2). Just bought the truck (2003 w/51k miles) when the service engine lighty came on. I will do the suggested cleaning of the MAF and replace air filter and do an oil change tomorrow (raining in sunny Florida today) and will keep you posted.

Walt

 

[umoms]

I replaced the Front Drivers Side O2 sensor and so far so good. Drove it for a week and 100 miles so far.

I talked to 2 other people who had the same codes and that fixed it for them. Try that out and let me know how it goes for you guys.