2003 Disco SE7 odd idle, have engine codes

[Ace Cafe]

After getting gas last saturday, 5 minutes later on the highway, service engine light comes on. Disco runs fine except for an odd shutter at idle every so often. Engine codes are:
150
174
0004
1100

I assumed I had some iffy gas, about 1/4 tank into refill and it still has a little shutter along with rotten egg smell at start up in the morning. I know i'm in due for a new air filter, is there anything else I should be looking for?

This was a small aspect of my LR weekend...along with the check engine light, I noticed later that morning that I was loosing coolant, pretty solid little pour. Made it about a mile from home before the engine started to get into the red. After topping off the coolant reservour, made it home only to witness the same steady pour. Long story a little less long...the o-ring had failed where the pressure side of the heater hose coming out of the intake manifold, was pooling and working its way to the rear of the engine then down the bell housing...95 cent o-ring was much better than blown head gasket. sorry for the long post...

Alex in Austin

 

[Chongo]

Grasping for air

Hello Alex. All of you trouble codes can be related to a dirty airfilter.................This may or maynot solve all the trouble codes. Change it and let me know......... Hope this helps...... Chongo

 

[Chongo]

Trouble with trouble codes

Alex: One more thing, Sometimes when a OBD2 diagnostic tool is used it will give a different description for the same trouble code. OBD2 diagnostic tools are not 100% effective in communicating with LR ECU’s

For example: OBD2 calls for a 0174 code to be lean which is wrong, per my t-4 diagnostics it states the system is too rich. Two different answers, one code. Be careful………. Chongo

 

[Ace Cafe]

got the airfilter on order...will update you on what I find...your comment regarding the lean-rich codes being similar makes since...the exhaust is certainly smelling on the sweat side...certainly more rich than lean. thanks for your post.

 

[wolf]

Alex: One more thing, Sometimes when a OBD2 diagnostic tool is used it will give a different description for the same trouble code. OBD2 diagnostic tools are not 100% effective in communicating with LR ECU’s

For example: OBD2 calls for a 0174 code to be lean which is wrong, per my t-4 diagnostics it states the system is too rich. Two different answers, one code. Be careful………. Chongo

Hi Chongo;

It's all part of the experience of owning a Land Rover! For example, my LR code book (please don't ask me how I got this) tells me that 0174 is, and I quote: "Sytem too lean bank B"

Wolf

 

[Ace Cafe]

replaced the airfilter (vaccumed out the leaves and sand from the bottom of the filter box, don't ask)...cleared the service light (via neg. battery cable)...came back on 5+ miles later. Still has the same shutter every so often and the exhaust is still smelling sweet with a nice rotten egg smell in the morning start-ups. Havn't pulled the codes again to see if any have dropped off since the air filter change.
Overall, the disco runs normal...except for the exhaust smell and the shutter. The shutter doesn't register thru the rpm's but you can definately feel it. Would a dirty MAF cause this? I've had O2 sensors fail on previous jeeps and it doesn't have the same loss of power feel...
may just bite the bullet and run it into LR.

 

[joey]

Dirty MAF, O2 sensors.. but the rotten egg smell tells me CATS are bad.

 

[Chongo]

In my Discovery manual Purchased through British pacific

Discovery Series 2 1999 – 2002 MY workshop manual

Covering 4.0 - petrol engines & td-5 diesel engines

Publication # VDR 100090

Description and operation page 18-2-32 and on

Under heading engine management systems - V – 8

States :

P0174 System too rich ( bank 2 ) ( Multiplication injector adaptive
Fueling rich limit exceeded
RH bank

P0175 System too lean ( bank 2 ) ( Multiplication injector adaptive
Fueling lean limit exceeded
RH bank

P0150 02 sensor malfunction ( bank 2 sensor 1 ) ( front sensor RH
Bank stoichiometric ratio
Outside operating band
(nas only ) )



P0004 Fuel volume reg. cont. circuit high.


P1100 Barometric pressure circuit out of range. This is most likely due to the leaves and dirt in the air intake system, plugged against the filter.



This is straight out of the book.


In your original thread you wrote 174 which is P0174

With my OBD2 diagnostic equipment it tells me the system is too lean, which I agree with you, but it is OBD2 diagnostics data. Not LR. and my manual codes are good through 2004 - D – 2 in this manual. This is why I say be careful with OBD2 diagnostic equipment.

I totally agree with Joey here

Per Joey’s statement : Dirty MAF, O2 sensors.. but the rotten egg smell tells me CATS are bad. He is right on.

What’s happened is due to lack of service to the air intake system, and probably other systems too, The starved air intake system allowed a rich condition to exist for some time. This will foul out the O2 sensors, and eventually plug the catalyst as well. Servicing the MAF sensor is a great idea as well to bring the vehicles performance back. You may also want to look at the plugs, I bet they’re needing replacement as well as the cats.

In a lean condition your Nitrous Oxide’s are high this doesn’t generally produce the cat smell your talking about, usually its the rich condition present with high CO’s an other elements found in unburned fuel deposits in the cats.

I’d like to see the Land rover publication you got a lean code from for a DTC P0174…………….. I can’t find a lean description for a Land rover DTC code P0174. But I can find one in OBD2
diagnostics………………………….. Be careful………………. Good luck……. Chongo

 

[Ace Cafe]

here's the latest...

tried to pull the codes yesterday before leaving work...no codes (----)

drove 45+ minutes, no engine light...5 minutes after restart, engine light pops on. Tried again to pull codes, nothing.

Same thing again last night when i headed to the store (to get large amounts of frustration wiskey)...light doesn't come on until second start but still cannot read any codes (----).

This morning, drove 60 minutes to work, no engine light, no studder, ran like a champ...i'll be curious if it pops on when i head to lunch.

Can the computer fix itself? I assumed once a code triggered the light, it will stay in the system unitl physically cleared.

whats the best way to clean MAF, O2's...oh, and where the he double L are they? MAF just downstream from air box? O2's in exhaust mani?

 

[Chongo]

check engine lights

Hello Ace Café,

#1 To start off with, if all sensors are in operating parameters, then yes, the processor will not turn on the check engine light, and yes the codes should stay in the system until cleared by a scan tool of some sort, unless there is a power supply problem or ground issues, or processor issues.

#2 Maf sensor is located in the air intake, just past the air cleaner It is the sensor in the plastic manifold between the air cleaner and the throttle baffle


#3 Maf sensor can be cleaned with electrical contact cleaner, but I use lacquer thinner with methyl ethyl ketones or aka = MEK. Probably not the healthiest thing I do for myself, but neither are cigars……: Do not use W-D 40


#4 Oxygen sensors are located in the exhaust system and look like spark plugs with wires attached to them.


I hope this helps………….. Chongo………