I purchased my s2k and it came with a megan header and nothing else, no cat no exhaust.

There is an o2 sensor plugged into the header but there is nothing else to plug into the high flow cat I just purchased.

Where does that second o2 sensor come from? Is it spliced from the first one and the previous owner just cut it off?

How can I remedy this problem of not having a second sensor to plug into the cat?

 

The connector is above the transmission around the shifter housing. Both O2 sensors connect to their own clip. You are clearly missing the secondary O2 sensor.

 

ok so I get a new 02 sensor and the sensor plugs into the cat and the other end above the transmission where you said. Is there a clip up there or do I have to splice wires?

 

There should be a harness unless it's been cut off. I'm surprised the ECU doesn't throw a code with no secondary O2 sensor reading.

 

oh there def is a code, the cel has been on since I bought it. I haven't had a chance to scan it since I threw it on jack stands.

i'll check tomorrow to see if there is even a harness, I couldn't find it today but I didn't look too hard either