ok so im pretty sure after researching on here this happens alot, so im hoping i can solve this. i recenty bought a 90 si with a b16a obd0 swap. the car screams like it should, except it studders once and awhile at a light cruising speed or pulling out. it also jumps to about 2400 rpm when i start it cold then calms after a few minutes to normal idle. after reading around, i saw the obd0 needs 2 o2 sensors... well of course i checked and i only have 1 sensor, right at the end of the header. it is a one wire which i guess is correct.

anyway i guess what im asking is this definitely the cause of both of my problems? or should i go through and check little things like distributor, fuel filter etc... i already ran fuel system cleaner through it twice and it def didnt do anything.

the only part that confuses me, is i thought if the o2 sensor thing is the problem, then the spark plugs should be different colors.. well i pulled them and only the one on the far left seems to be slightly darker... so hell i dont know. any suggestions are greatly appreciated.