Hi all I have recently purchased a Range Rover Vogue 2004 everything working but engine management light keeps coming on showing codes P0174, P0171 & P056 which I believe state lean burning, the vehicle is on LPG. Can anyone advise as to the best way to cure these codes as they normally come on after about 8 - 20 miles after being reset. Spoke to a local 4 x 4 garage whos said this is common and not to worry bout it! but understand that if the engine is burning lean it can cause damage to valves and pistons, and advise welcome. :lalala:

The codes could indicate a problem, and then maybe not. A LPG specialist to check the LPG system. if a air leak and if you ARE burning lean, you could end up with burnt valves

The garage are telling me it's just sensor issues end engine not burning lean is there any way I can confirm this, there are no leaks on the lpg system just wnat piece of mind.

He wasn't saying air leak in the LPG...he meant an air leak on the induction side of the engine....

On the L322which has the M62TUB44 BMW derived engine, the most common vacuum leak is the PCV valve on the rear of the Intake Manifold...the diaphragm inside splits allowing unmetered air into the induction system that the ECU hasn't allowed for causing a lean mixture...

Second common are the intake manifold seals, they go hard and brittle causing air leaks...again weakening the mixture....then thirdly is the throttle body seal or a split duct after the MAF.

To test, remove the acoustic cover and using brake cleaner or similar flammable aerosol (wouldn't advocate easy-start) and spray the intake ducting after the MAF, the throttle body, the intake manifold lower recesses, the PCV valve on the rear...if the idle speed/note changes, there is an air leak causing lean mixture.

Failing that, get the LPG system re-calibrated and take it to a different garage....it should NOT be like that if setup correctly...I have had my L322 on LPG for over 2 years and the EML has come on twice for a Lambda sensor out of range and both of those were after wading!!

Many thnx for the advice may I ask once the Lambda sensor was changed did this cure your issue. Regards,
Kev...

BhamKev said:

Many thnx for the advice may I ask once the Lambda sensor was changed did this cure your issue. Regards,
Kev...

Click to expand...

Didn't change the sensors....the fault was caused by wading through water....once dried all is well

What I am saying is, that a correctly setup LPG system should not bring on the EML....mine never has, and the only time the EML has been on is after a couple of dips, that garage who told you it was common and not to worry is wrong...and I suggest finding somewhere else to take your pride and joy.

It could be the Lambdas giving wrong info back the the ECU...but before you change them out (there are 4) I would suggest checking for induction leaks and getting the LPG properly calibrated...if it still happens, then it would be time to check the Lambda sensor operation