XSeries-forum

Here are the current codes the 05...m54 B 30 is facing with 225k on the clock...
P0 174
P0 171
P0 442

What scanner are you using?

Those codes look like generic P-codes rather than BMW codes.

P0174 comes back as “mixture too lean, Bank 2”. As you only have a 6-cyl engine, you don’t have a ‘Bank 2’ as that’s a V8 thing.

P0171 is ‘mixture too lean’. It might be right for a 6-cyl. Points at an issue with the mixture control but doesn’t give any more than that.

P0442 is a ‘leak in the evaporative emission control’ - stops petrol fumes escaping.

If you can get hold of a tool (borrow) that gives the BMW error codes, that will help narrow things down a bit. I use Carly but that’s a paid for product and you have to use their Bluetooth/wifi dongle. You may find someone local with the kit.

Running too lean is sometimes a leak in the rubber trunking between the airflow meter and the inlet manifold , its reporting the lambda is out of range of adjustment due to too much unmetered air getting in so there is probably an airleak somewhere .
The evap system could just be the "gas" cap isn't sealing anymore .

All very accurate info.
I'm using the BT Dongle Torque pro software...
It's my last resort seeing I don't know how to update my foxwell... I'll tend to that later.
I did spray the return valve with break cleaner found initially it wasn't completely snapped in.
Didn't take the time to clear the codes yet. If the codes don't come back then I won't have to go hunting. I changed the gas cap 1 week ago.