Z3 1.8 M43 EML Code Help

[Alan Patterson]

Good Morning

Hope someone can help me with this one.

Over the winter I had my 2000 1.8 M43 Z3 off the road and fitted a complete after-market exhaust. It was a good quality IMASAF manifold back system from Germany, although Italian built. Refitted original pre and post cat sensors.

Back on the road in March and when it gets up to a high enough temperature to operate the colling fans ie fast run then slow traffic, the EML light comes on. I plug in the C310 Creator code reader and I get the following (in this order)

-Oxygen-senor control, control limit (EUIII code P0170)

-Catalytic-Converter Conversion(EUIII code P0420)

-Activation, map cooling


Prior to buying the car, it looks (from the receipts) that the previous owner had some EML issues and has had a garage replace:


MAF Senor (8kg reading at tick over)

Breather Pipes

Vacuum pipes

Thermostat

Spark Plugs

Radiator

Cooling Fan

Front & Rear Cylinder Head coolant elbows

I am tempted to replace the pre cat O2 as according to web forums, it often is the trigger or is all this related to the non-type approved cat. Is there a way for the car ECU to learn the new parameters? I deleted adaptions so that it would “relearn” but still the light comes on.

When I was on a fast A-Road run at the weekend, the car momentarily stumbled, lost power for a few seconds and the EML Light came on with these codes above. When I erase them, they come back, sometimes with no power loss symptoms. Sometimes the idle can be a bit lumpy when hot but nothing dramatic.


Has anyone had this and managed to solve it. There seems to be multiple stories of owners replacing everything and not getting a solution! Wonder what the map cooling has to do with it? My understanding is that it’s a sensor/element on the thermostat housing that fails?


Many thanks!


Alan

 

[Alan Patterson]

Oh, one thing I hadn't added. It sailed through its MOT emissions test in April so assuming CAT was within spec.
Cheers
Alan

 

[colb]

My M43 had an occassional EML when I bought it, went through part by part camshaft sensor, exhaust pre and post cat (Bosch items not cheap pattern parts). Original sensors were slow when viewed on diagnostics so changed them out. Finally sorted it by replacing the Maf for a genuine BMW part. Transformed the car when fitted and been spot on ever since. Always replace parts with oem quality parts, cheap pattern parts don't last or even work at all.

 

[Alan Patterson]

Thanks. I notice the new MAF fitted by the garage last year was £88 + vat. So not sure if that was a Bosch one. Will check it.

 

[Stevo7682]

My m43 had the p0170 fault replaced the sensor all good since
Stephen

 

[t-tony]

Thanks. I notice the new MAF fitted by the garage last year was £88 + vat. So not sure if that was a Bosch one. Will check it.

I would imagine at that price it would be an aftermarket MAF Alan.

Tony.

 

[t-tony]

Thanks. I notice the new MAF fitted by the garage last year was £88 + vat. So not sure if that was a Bosch one. Will check it.

 

[colb]

Would agree at £88 sounds like an aftermarket one, shop around for a Bosch or Seimens branded one if yours is suspect. BMW was well over £100 when I had mine. Sourced my Lambda sensors at Euro Car parts, they sell them in a sealed bag once opened no refunds. They were Bosch sensors.

 

[Alan Patterson]

Thanks Stevo. Do you mean you replaced the MAF sensor? Cheers.

 

[Mario]

Hello. If you need a MAF to try I have a known good second hand one original BOSCH / BMW that you can have for cheap.

 

[Alan Patterson]

Thanks Mario. This weekend I am going to remove the " new MAF" that was fitted by the last owner and see if it's a Bosch. The side of the housing I can see suggests it is, unless the actual sensor part has been replaced and isnt Bosch. How much would you be looking for yours and is it the M43 one?

Thanks
Alan

 

[Mario]

Yes it's the m43 one for sure I can check the part number later on. 35 delivered?

 

[Mario]

Just checked and its the right part number original BOSCH if you need it let me know

 

[Alan Patterson]

Thanks Mario. Do you know how many miles roughly the MAF has done? Did you take it off a car or did you buy it as a spare unit? I take it the car it is off was running well with no EML light?
Alan

 

[Mario]

Yes it's a known working one no eml, I recon between 80 and 90k. I got it to troubleshoot a problem with a car that I owned that ended up being a vacuum leak after fixing the leak I cleaned and tried both mafs and they offered good readings on inpa when I plugged the computer. I wish I could plug the computer again to show you but that car is gone. I understand you have a computer to read maf values? If that is the case it will be easy for you to read maf values on your one and my one on idle and under load and figure things out. If you don't feel confident about buying this maf from me it's OK no hard feelings.

 

[Alan Patterson]

Happy to go for it I just needed to know it was A known quantity. I use A C310code reader with data stream so will check outputs on my existing one A spare is always handy to have. I've paid you via PayPal before for the Nexen tyres. Do you still have my address? I can PM you with it if you need it.

Many thanks.

 

[Mario]

Yes please pm me with the address