91EF919

I have a 91 civic std, with a obd2 ls swap, converted to obd1. I have a hytech replica header, ebay CAI with k&n filter, advanced timing, and 2.5" all the way through no cat no resonator. I am running it with no o2 sensor, i noticed i am running really rich, and mpg is like a at 18-21mpg. I was wondering what type of o2 sensor i would need. I sent my harness to rywire, and i see he o2 sensor plug and its a 4 plug sensor, what year o2 sensor will i need?. And has running no o2 sensor really damaged my motor a lot?

Italix

you just need an obd 1 or newer O2 sensor, they come with the 4 wire connectors.

91EF919

ok thanks, and where can i find the ngk ones on here? I heard they are like $50, will it make my car run better, or any faster??