I am codeing just one long flash i was told it was my o2 senser. Are the obd1 and obd2 o2 sensers the same. The exhaust i got had two sensers in it i know i only need to run one. I swaped the back to the front but it is still codeing o2 senser. I dont know if i am running the one or if it is just bad any help would be good.