i just did a d15b swap in my 91 si and i go to put on the fan and it just hits the o2 sensor on the header. i tried notching it but it wont work. is there some kind of slim fan or something that can be used?
thanks

 

I think ive heard of people plugging the o2 sensor hole and welding in an o2 bung onto the cat.

yeah there a tons of aftermarket slim fans, just make sure the fan you get is a "puller" and not a "pusher".