O2 sensor problem?

[rated- r]

I did a b16 swap on a 91 hatchback. I'm trying to make it smog legal(I live in California by the way). I got everything except the stock exhaust manifold off that engine. I heard i could get it off a 94 del sol v-tec or a 94 integra, but not sure. Can anybody help???

Also, what's the deal with the 2nd O2 sensor? Going by the b16 wiring diagrahm, it calls for the 2nd O2 sensor. From my understanding, the 2nd O2 sensor is for a OBD2 system. So, Im comfused. Do i need it or not? And how would I install it on the exhaust if it only has for one O2 sensor? Sorry for being so confusing!!!!

[2CrX]

You can do one of two things with the second o2, weld a bung for it in the exhaust, its the same sensor as the one on original crx motors, just a diff plug. Or splice it to the other o2 sensor, this I dont recomend.

[Kven]

does your ecu use the 2nd O2 sensor? better yet, do you know what OBD ecu you have? if you have a OBD0-1 then you dont need it; atleast i dont think so. i dont know too much about cali laws.

[1990civicdxhb]

my header came with the 2nd 02 sensor hole,
you may not need it,(I'm not too sure being that its a b series)
the best way to get rid of it,
I put a 2nd 02 sensor in that hole,cut the wire & leave it alone,
I have an extra 02 sensor that still works,(bosch)
if you come to find out that you dont need it,
make me the smallest offer & its yours.

[bambam89lx]

yes, the obd0 pr3/pw0 b16 ecu's do both use secondary o2 sensors. I definitely recommend you get a second o2 sensor bung welded in.

[rated- r]

Thanks for the help! I was searching online and found that hasport came out with headers that accommodate both O2 sensors for the b16 swap. Has anybody seen that? Not sure if its smog legal though.