ECU interchangeabiliti
 

Ok, short story :

My winter beater is S4, running on N326 ECU and approriate sensors. From time i put it together, i had problems with timing. It was firing like 20 degrees advance, no split. Being it NA for winter driving, let it be and been driving car. Even without O2 sensor at all, gas mileage was great, around 10l/100km.

Today i have been at shop and wanted to find out whats causing that weird firing, i started checking things and did not found anything. Well, i took S4 TII ECU (N344 - Euro one, but interchangeable for N332 or N333) and installed it there in place of N326. Everything else remain same (NA harness, NA injectors etc...). Car started up and bingo! Timing was firing correctly now. I took car for drive and shortly after flooring it noticed fuel cut! Yeah on NA. Of course, NA pressure sensor is different than TII one. Ok, turning back, swapping NA pressure sensor for TII boost sensor and here we go. Now it runs all the way to redline and is pulling nicely.

I will be driving on TII ECU now and will check gas mileage (still without O2 sensor), hopefully it will not be that bad since i am still running on NA injectors. Will see.

Never knew u could run NA block on TII ECU so smooth - considering its different compression ratio, different ports and different injectors....

Just tought someone might find it interesting.

Thanks for edifying us, hIGGster- you are the man!!

I am rather skeptical that everything would work on a car equipped with full US spec emissions and BAC.

There are some key wiring differences between the two ECUs.

Perhaps your Euro Spec non turbo, has less wiring than the US spec.

Not that i am aware of. S4 US spec turbo and S4 Euro spec turbo is pretty much same - thats the reason we are able to interchange any parts or harnesses between them.