ok so this buddy of mine has a 90?? integra rs, its obd0 i know but anyway he was having shitty mpg and a hesitation every now and then, he was running a dc header with the o2 down in the collector with a 1 wire o2. i suggested he switch to a heated o2 since the current one probably wasnt getting a good reading down in the collector.

well today i wired a 4 wire o2 in and now he is getting a #43 cel fuel supply malfunction or some thing and im unsure what could be causing this. the car seems to run smooth and everything...

i wired the o2 with the white wire to the ecu signal using sheilded wire, one black wire is going to a jumper harness i made up to draw current from the coil, the other black wire and green wire run to ground so my wiring should be correct. but i was told be someone that the heater should be run using a relay and run to the battery? and someone else said that it shouldnt have continous voltage? dont know if thats right or not..

the o2 we used was a used honda he got form another member on here so unsure if it may be bad?

we also where going to put a new exhuast on but test pipe that was made didnt fit so he is running open header. he said this gave him a o2 sensor cel before..

the car was also seafoamed today and like 1/3 can was put in a tank on about 1/4 full dont know if that would make a problem or not..

and 2 weeks ago we swapped out injectors from a crx si no code then though...

so does anyone have any insight on where i should start digging to get the code fixed??