Hi man,
I have just had the same thing happen to me and you wouldn't think it possible but to both of my R34s (a 98 and 2000 model). Their not turbo so I only got the engine light.
It turned out to be the coils...... No: 4 on one and No: 5 on the other.
I did a self diagnostic and had error code 21 and/or 33.
Replaced the bad coils and all sweet again.
Hope this may help!!