Ok guys i was wrong on the engine. I thought it was the y5 because all the oil change receipts put the y5 down. The block is a d16y7 and the tranny on one side says e5f and the serial shows s40. Does the y7 require 2 o2 sensors as well? The engine has 2 o2 plugs so im not sure. I also see it is not vtec so would a vtec head b a good investment or should i jus use it as is and turbo it?
I wasn sure if it would be worth it or not. I saw there was maybe 12hp gain if i had they y5 and went to the y8 head. And i was confused on the sensors because it was made to sound like the only one 96-00 that had two was the y5
Like said over a week ago by @XpL0d3r, ANYTHING OBDII is going to be 2 O2 sensors. Unless the car was swapped and reverted back to OBDI for tuning purposes, it will need 2 oxygen sensors and a cat inbetween or it will throw the codes.