P0171 - P0174 fault codes

Hello,

I have had this problem for a long time. My 4.0 V8 is strugling at high revs / running flat. The codes that are shown are bank 1 lean and bank 2 lean. I have rest the codes a couple of times. It runs fine after the codes have been reset and then it slowly gets worse by holding back. so bad that every bank I hit the gear box has to kick down. i have tried cleaning the ait flow meter. I haven't looked for air leaks as it idles fine. I believe the O2 sensors to be ok as the problem is showing on both banks.

Can you help please?

What equipment are you using to reset the codes ? Can you view live data ? I cant see why clearing codes helps as it is just a memory reset. Air flow meters are the usual culprit for Thor injected V8's,but often dont log codes.Dont fall into the £50 E-Bay replacement trap - they are rubbish.Better to borrow a known good one then buy a geniune one if it fixes it.Are you running LPG ?

eightinavee said:

What equipment are you using to reset the codes ? Can you view live data ? I cant see why clearing codes helps as it is just a memory reset. Air flow meters are the usual culprit for Thor injected V8's,but often dont log codes.Dont fall into the £50 E-Bay replacement trap - they are rubbish.Better to borrow a known good one then buy a geniune one if it fixes it.Are you running LPG ?

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hi mate,

the scanner I use doesn't show live data but I can borrow a bosch KTS system. I don't know anyone I can borrow one off. Not LPG just petrol

thanks

KTS should get you live data,but I still dont think it will help - borrow an air flow meter off a good one and try it.If that does not work use the KTS to watch your oxy sensors.

well I put a new bosch air flow meter on today. she runs like a new motor!

Invoice to follow !

Nice one lads! I had the same problem with my Series 2 Disco and followed your tales, but I read on t'internet that you can clean the MAF sensor with contact cleaner fluid. I stripped mine down and cleaned it within 10 mins - It runs like a dream now! Cheers Lee