yellowbird

I got a ported TP from jantzer last summer and 3 times this last fall it would threw a po121 code,telling me Its the TPS,so I changed It,bam the code again.I was told Its because the Idle screw Is not set right,heres my question,does anybody know where that screw should be set at and how many ohms should show on a ohm meter,Im tired of seeing that f###ing SES light.! thanks.