Engine swap on a 318ti Msport
 

Hi, I have a 318ti msport on which I have started a swap. I bought a m50tub25 out of a 93 325 from a friend. He was in a rear in accident. I am rebuilding the engine and am using forged internals from a 05 330. I have already started on the deconstruction of both engines and they both seem very clean on the inside and look good. I do have one question if anyone can. I have 2 ecu I can use. The one from the 325 or I have a 95 M3 ecu which is tuned. I was curious if I can swap the chips, but the M3 has ewsII on it. Would it carry over? If so I may just use the M3 ecu and get a ews delete chip. Then as well does anyone know how to delete 02 sensors for either ecu setup on obd1?

Thanks for your time. I will update my build as I progress and post pictures next weekend. I probably will part out my m44. It was pretty up and going little engine and I will probably miss it a little.

You first have to ask yourself whats the setup that the M3 "tune" is for ?

Is it a red label 413 or a silver label 413?

If its a red label then EWS delete is simple no chip required.

Why would you want to delete the O2 sensors ?

The only time you need to do this is when you are running OBD2 headers on an OBD1 engine but then you just block them off and run the one downstream.

Swap
 

I have one non ews red label ecu from a 325is and a ews silver label ecu from a m3. Which ecu is better? Will it run fine on a stock 325 eci

Run the Red Label 413. It'll work just fine.

Theres no difference between the M3 413 and the 325 413.