What are the side effects of replacing the MS43 DME ECM?

[Clavurion]

What are the exact codes you are having? Most of the pre-cat lambda errors on M54 engine are caused by air (vacuum) leak.

You can't just change DME. Immobiliser data on DME has to match your vehicle or it won't allow engine start.

[Mike1261]

Originally Posted by Clavurion

What are the exact codes you are having? Most of the pre-cat lambda errors on M54 engine are caused by air (vacuum) leak.

Attached is the error code screenshot I'm getting on INPA.

It's been this way since I bought the car, the O2 sensors have been replaced twice, both times with Bosch.

[Clavurion]

Originally Posted by Mike1261

Attached is the error code screenshot I'm getting on INPA.

It's been this way since I bought the car, the O2 sensors have been replaced twice, both times with Bosch.

Most likely air leak causing too lean mixture. DME is trying to give richer mixture according to lambda signal but not able to do it.

Typical air leak causes:
*Rubber boots between MAF and throttle valve
*CCV hoses/separator
*Rubber plugs at the rear end of intake manifold
*DISA valve

[Mike1261]

Originally Posted by Clavurion

Most likely air leak causing too lean mixture. DME is trying to give richer mixture according to lambda signal but not able to do it.

Typical air leak causes:
*Rubber boots between MAF and throttle valve
*CCV hoses/separator
*Rubber plugs at the rear end of intake manifold
*DISA valve

The boot that attaches to the throttle body has been replaced.

New CCV system.

Replaced the O Ring on the DISA Valve and cleaned it thoroughly.

So I'll check the rubber plugs at the back of the intake manifold. Hopefully it's as simple as that lol.

If there's any other common vac leaks you can think of I'm happy to check those too!