[pSyCoSiS]

Hi there,

I have previously posted regarding this issue....

My old man has a 2001 530i Sport Auto in Individual Velvet Blue, Champagne Nappa Leather, etc.

A few months ago, it developed a rough idle when in traffic. Engine light came on.

No error codes for Oxygen / Lambda Sensors.

Inlet Manifold was removed. 2 Pipes were perished, and these were replaced.

Everything put back together - problem still there, engine light came on.

Garage then pointed out it could be the DISA / Adjusor Valve.

£150 from BMW - replaced the part, issue still there! (albeit, the car engine is less noisy, as the old DISA flap was loose).

On the diagnostic again, and I have been told these were the error codes:

CA Limit Bank 1

CB Limit Bank 2

E4 Bank 2

E4 Bank 1

Does anyone know what these error codes translate to, and what needs to be done / replaced in order to help resolve this issue?

Many thanks.

 

[jonnybgud]

E4 DME Fuel trim bank 2, Mixture too lean
E4 DME Fuel trim bank 1, Mixture too lean

as for CA Limit Bank 1, CB Limit Bank 2 I cant seem to find these in my database of fault codes but i would think these are to do with oxygen sensor limits due to rich running (too much air)

I would think you have an air leak somewhere by the looks of it, best thing is to get a smoke test done on the intake system, this way you will see any leaks you may have

edited to say found what the CA/CB codes mean... DME -> CB/71 - Oxygen sensor control, bank 2, control limit, mixture limit rich. CA/71 - Oxygen sensor control, bank 1, control limit rich

 

[TheEnd]

Yep, it'll be an airleak somewhere.

 

[pSyCoSiS]

So you think it's definitely not one of the sensors that have gone?

Who should be able to do a smoke test?

 

[TheEnd]

I can tell you now it is 100% not the sensors, and if any garage tells you it is, remember never to go back there again.

Not sure on the smoke test, but an unsteady idle means there is a decent leak that you might find by spraying carb cleaner about the engine and seeing if you can hear the engine note change as it sucks some in.