I recently had a header and exhaust installed on my 98 DX Coupe.

I noticed the Oxygen sensor at the end of the header is not plugged in to anything.

I also notice a plug next to the upper sensor that is not plugged in to anything.

Logic says they should go together but I want to be sure.

Anyone know the colors of the plug from the ecu to the lower oxygen sensor?

The car ran great for a month but now when it gets warm it feels like it's running out of gas.

If I let it cool it is good for another 10 mins or so.

I just put an aluminum radiator because the old cap wasn't tightening and the radiator was old.

I also just did Cap and Rotor and an oil change. I haven't driven it since the day those problems happened 2 weeks ago.

I basically want to know where to hook up the lower oxygen sensor and what problems would come from a disconnected oxygen sensor.

TIA