On 95 318i I just changed o2 sensor reset computer by disconnect negativ on battery for about 1 hour. when I connect battery back and started car after 30 second came check engine light again when I put little gas go away but 30 second later came again. I scaned computer by turn key on and step on gas 5 times and show me code for o2 sensor again (1222)Do you know what yelse can be wrong????