So i bought 4 wire oxygen sensor frorm rywire and when i looked into my ecu pins the pins that were suppose to be free for the o2 to be wired to are already full with wires. should i take them off or splice them ?

 

It would be helpful to know some car info...

 

Splice them, some of the grounds and 12v are shared

 

94 Eg b18 swap obd1 ecu