M52 OBD2 swap without re-tune

[Panici]

Planning to swap an M52B28 into my E30 once I have all the parts together. (hopefully later this summer)

Would a stock M52 ECU have any issue (pulling power, timing etc) running the motor with EVAP stuff, SAP/SAI, CCV, ASC, and Secondary O2 deleted? I don't care if I get a CEL. (No emissions check, car is old enough)

I would probably run secondary O2 sims. I can leave sensors/pumps electrically connected if that will make the ECU happy.
I'm swapping the EWS stuff over.

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I plan to run Megasquirt a few years down the road (with a turbo setup). I wanted to run with the original ECU until then.

If the stock ECU is going to get mad and limit the performance of the motor, then I might as well just run MS when I swap the motor, rather then dumping money into tuning the stock ECU for the swap.

[justin_l_]

AFAIK it should just trip the CEL. If you eliminated the front o2's that would be an issue. ASC does nothing, CCV shouldn't affect it, evap is useless. SAP will just trip a CEL as well. The downstream o2's are just checking that the cat is still working properly. I wouldn't think that it would cause a limp mode situation, but if you were that worried just run a simulator.

[Panici]

AFAIK it should just trip the CEL. If you eliminated the front o2's that would be an issue. ASC does nothing, CCV shouldn't affect it, evap is useless. SAP will just trip a CEL as well. The downstream o2's are just checking that the cat is still working properly. I wouldn't think that it would cause a limp mode situation, but if you were that worried just run a simulator.

Thanks! Looks like I'm good then.

If I need rear O2 sims, I'll probably build something like this.

http://mkiv.com/techarticles/oxygen_sensor_simulator/index.html

[Poeman446]

I reflashed my ECU myself to remove the SAP, rear O2s and the EWS. No CELs from me and my S52B32. I posted a thread on how to do it, but I don't know how to flash it because it's a little different. If it were me, I would send it to Dave at Makert Motor Works to get retuned. He taught me a little, and is a genius with these things. He can probably tune you up to go with a M50 manifold as well. Look for 328i Junkie on here. Removing the rear O2s is literally one byte of code, and isn't difficult at all. I'd honestly recommend that.


I understand reflashing can get expensive, and if I get set up to reflash again and I learn how to do the ms41.1 ecus, I'll hook everyone on here up for cheap.

The only thing you'll get without a reflash is a CEL. Other than that, no issues.