SES Light

[ZZROCOOL]

SES light came on a few weeks ago, with a little bit of a ruff idle. I scanned the codes and got the following
P0171
P0130
P1171

all relate to lean O2 sensor readings

I replaced all 4 O2 sensors and light reset the light and it came back on after about 65 miles reading same 3 codes. My assumption is the MAF is the issue any ideas? 2003 Disco II

 

[joey]

Depending on miles and last tune up, then if I were to guess I would say MAF.

 

[Disco Mike]

That 130 code will only effect the drivers side bank and possibly cause the 171 code, I would call and get the 02 warrantied. As for the 1171, I would wait that one out before you throw a new MAF at it, and don't try and clean your MAF or you will be buying a new one for sure.
Wait and see if any other lean or tranny code comes up before you consider a replacement.

 

[ZZROCOOL]

Truck has 91000 on it i drove it around for almost 3 weeks prior to installing the new o2 sensors and the only codes were those 3.
Plugs were changed 10k ago

 

[Chongo]

L-H bank

SES Light

SES light came on a few weeks ago, with a little bit of a ruff idle. I scanned the codes and got the following
P0171
P0130
P1171

all relate to lean O2 sensor readings

I replaced all 4 O2 sensors and light reset the light and it came back on after about 65 miles reading same 3 codes. My assumption is the MAF is the issue any ideas? 2003 Disco II




Hello ZZROCOOL:

PO130 Tells me on the left hand side of the engine bank 1 sensor 1 is too
Rich. Technically speaking, the Stoichiometric ratio is outside the
operating band. This is what the O2 sensor is reading.

PO171 Multiplication injector adaptive fueling Rich limit exceeded L-H bank.
Basically means Closed loop learned fueling limit exceeded.


P1171 Multiplication injector adaptive fueling Rich limit exceeded L-H bank.
Basically means Closed loop learned fueling limit exceeded.


When a vehicle is made all dealers engineer many different strategies permanently programmed into the ecu. These programs are open loop and also for closed loop operations. In open loop the engine relies on some sensors, however some sensors are not to operating temperatures yet and their data is useless until they reach a minimum operating temperature. The strategies learned by the processor that are not pre programmed by the manufacturer are called adaptive data or strategies, and are the fine tune adjustments for your engine. Since all engines are not exactly the same this fine tuning adaptive learning ability helps satisfy your engine needs, especially in areas not programmed in..

A plugged air filter will make both banks read rich, and a fouled maf sensor will do the same, or the opposite, lean but the same codes for both sides, banks, and treat both banks equally. This is not the case here, one bank and only, the left bank is rich, The right bank is performing well, there are no codes for the right bank with your posting.


1: What I would do is pull the left bank plugs, and keep them in order. Check the condition of the tip of the plug in the combustion chamber, and tell us is it oily? Are you loosing antifreeze? Are they black? Sooty? Please describe or send pictures.

2: Repeat step one with the L – H bank O2 sensors and let us know.

3: Repeat steps 1&2 for right hand bank.

4: Compression and leak down test on all 8 cylinders .



Just some possibilities:

1: ECU
2: stuck fuel injector and wiring.
3: valve guides
4: piston oil control ring and piston blow by.
5: head gasket
6: defective new O2 sensors or wiring.
7: Grounds and wiring, L-H bank
8 plenum, manifold gasket vacuum leak, ( leaks in pressure differentials)


Best wishes, let us know…………….Chongo

 

[ZZROCOOL]

Update

truck has 91k on it
plugs done last year

after the o2 sensors were replaces I am just only throwing 1 code p0130
does that narrow it down
car is not loosing coolant or oil

 

[Chongo]

Update

truck has 91k on it
plugs done last year

after the o2 sensors were replaces I am just only throwing 1 code p0130
does that narrow it down
car is not loosing coolant or oil



I rarely recommend this however, Since you ran on the old O2 sensors for quite some time, some of the adaptive data may be in error, ( they adjusted to the worn condition of the old O2 sensors ), Disconnect the battery before you go to bed, and connect it back in the morning, this will purge all adaptive data, and start off with clean accurate data.

Did you check the plugs?

Best wishes ………….. Chongo

 

[ZZROCOOL]

I'm gonna replace the plugs
air filter and the MAF (got a brand new one for free)

and see what happens