OBDII code inconsistency...

2000DiscoveryII · Apr 1, 2008

Does anyone know the meaning of these codes...

P1171- Dealership said "rotor sensor fault". other sources say it means bank 1 too rich.

P1174- Dealership says it is a "cam sensor fault" others have said this means bank 2 too rich.

Anyone know for sure?

I also have code P0455 which I was told is an "Evaporative Emission Control System Leak Detected (gross leak)"

My 2000 Discovery has 111,000 miles on it. At about 90-100K I replaced or did the following to the engine system...

-Spark plugs
-all 4 O2 sensors
-new MAF
-sea foam treatment

Any idea what might cause these codes? I am going to replace the gas cap to hopefully get rid of code P0455, but the cap and seal look to be in good shape.

Chongo · Apr 1, 2008

OBDII code inconsistency...

Does anyone know the meaning of these codes...

P1171- Dealership said "rotor sensor fault". other sources say it means bank 1 too rich.

P1174- Dealership says it is a "cam sensor fault" others have said this means bank 2 too rich.

Anyone know for sure?

I also have code P0455 which I was told is an "Evaporative Emission Control System Leak Detected (gross leak)"

My 2000 Discovery has 111,000 miles on it. At about 90-100K I replaced or did the following to the engine system...

-Spark plugs
-all 4 O2 sensors
-new MAF
-sea foam treatment

Any idea what might cause these codes? I am going to replace the gas cap to hopefully get rid of code P0455, but the cap and seal look to be in good shape.

Your right, OBD2 is not 100% compatible with the Rovers DTC which is in violation of the congress bill they passed for OBD2 for you lawyers out there………..

P1171 = {system too rich bank 1} additive injector adaptive fueling rich limit
Exceeded LH bank

P1174 = {system too rich (bank 2) } additive injector adaptive fueling rich limit
Exceeded RH bank

This could be a dirty air filter or a maf sensor that needs cleaning

As far as the P0455 code goes, gross vacuum leak in the evaporative system. Check all hoses, and make sure the fuel cap is on correctly, and tight.

Hope this helps……….. Chongo :bandit:

2000DiscoveryII · Apr 1, 2008

Thanks, that does help.

I just went to O'Reilly's and bought a gas cap for under 7.00. The dealership wanted close to 50.00. The only difference I could find between the caps is that the OE cap is teathered and the aftermarket one is not. It did feel like it sealed better, but visually the old cap looked fine to me. I guess we will see.

I will replace the air filter since I have a brand new Mass Air Flow unit and see what that does.

Thanks again, I will post my results incase anyone else out there runs into this problem.

2000DiscoveryII · Apr 3, 2008

I am still getting the 1174 and 1171 codes with a brand new bosch MAF and brand new air filter. 0455 went away though. I guess I will start looking for a vaccume leak?? Does anyone know the proper procedure for this or have any tips/suggestions? Thanks!

Chongo · Apr 4, 2008

I am still getting the 1174 and 1171 codes with a brand new bosch MAF and brand new air filter. 0455 went away though. I guess I will start looking for a vaccume leak?? Does anyone know the proper procedure for this or have any tips/suggestions? Thanks!

Usually in a rich condition a vacuum leak is not what your looking for, this would give you a lean condition, and lean codes, not rich. P1172 and P1175 are lean codes. In this case where you have a rich code, The processor could be compensating for a vacuum leak by adaptive strategies

Is the engine idling high? Around 1200 rpm or low?

Has the engine been loosing power ? gutless?

Last tune up and plug change ? and mileage on wires and plugs.

Does it seem to be missing at all?

Have the HO2S, O2 sensors ever been replaced? And how long ago?

At this point some of the possibilities are as follows:

1 Oxygen sensors, Highly likely the problem. Test them first with ohm meter, and make sure the heater circuit is working.
2 Cats plugging up, check back pressure = gutless question
3 Faulty iacv stuck in a default position. This is why I’m asking the high or low idle question.
4 Miss fires plugs not always lighting the a/f mixture.
5 Coking: this is where the intake is very oily inside, usually due to the crankcase ventilation system……. Pronounced: coke…. ing
6 Ring and or valve guide issues.
7 Although rare, injector or injectors stuck partially open.
8 Faulty coil pack, intermittent problem only.
9 Block or ground issues
10 Faulty processor
11 Fuel soaked Evaporative canister.
12 Fuel pressure too high.
13 Iat sensor out of range ( Intake air temperature )
14 Restrictions in intake

Let me know………. Good luck Chongo :bandit:

2000DiscoveryII · Apr 4, 2008

Thanks for the suggestions. I found a leak at the throttle body gasket. Used carb cleaner to find the leak.

I fixed the leak and the codes seem to have gone away. It has only been about 35 miles since the fix so I guess we will see. If this is not the fix then I will let everyone know incase there are others out there with a similar problem.

Once again, I really appreciate your time!

OBDII code inconsistency...

2000DiscoveryII

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Chongo

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2000DiscoveryII

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2000DiscoveryII

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Chongo

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