header situation

[4DRonDUBS]

This girl i know took off her dc sports header and the sensor was stuck in it, so she just cut the wires and installed a stock header on her civic coupe dx. she connected the cut o2 wires on to the stock header o2 sensor she started her car and got a check engine light....
I thinkshe connected the wires back up right. A bad o2 sensor can cause this to right... The two grounds were never marked different from each other she might of hooked them up wrong. could that cause it eather.

 

[H22AdelSol]

Doesnt the 02 sensor have a plug? Im pretty sure those o2 wires are shielded and wont keep the same ohms they are supposed to have if they are soldered.

 

[Arachnid]

Did she disconnect the battery first before cutting the wires? Did she reset the ecu by disconnecting the wire from the battery?

 

[cycloneb18c3]

i just cut and soldered my 02 sensor wire because i had to extend it for my header...