2009 SX4 164xxx miles. Girlfriend asked me to look it over because it, "sounded crunchy"
. Needed oil. She ran about 5k miles without an oil change and i believe she is not using synthetic at the moment. Coolant wasn't topped off so I added to full line. I also discovered this rouge wire not plugged in to anything. Her A/C doesn't blow cold but the system is charged and fans/blowers work. Her check engine light is on with the P0420 code. Manifold cover seems like it is missing the bottom bolt and rattles a bit on idle. I can smell (just slightly) some exhaust fumes near the manifold, but am not sure if it is cracked or if that is normal for these cars. I believe her water pump pulley has some sort of ding or slight bend on it about 1 CM wide. Pulley seems fine other than that bend, doesn't wobble or screw with the belt. No overheating or irregular temperatures to note. Other than that, the car sounds like it runs fine to me. No audible loudness originating from manifold or flex pipe or anything in the exhaust system. After I added some oil the lifter tick went away. No irregular smoke colors coming from the exhaust. No other odd noises or smells to note.
The wire pictured seems to be in the same harness as the spark plug wires. I can't fit under the car to see where it might have been disconnected from and I don't have any jack stands at the moment. My first thought was that it had something to do with the A/C system, but form what I have been reading, it seems like there is an O2 sensor that could be causing her code and I am wondering if this was disconnected from it entirely. Thoughts?
From what I have read about that engine code, the problem could be a myriad of things. Will most likely have her take it to a mechanic to check if her engine code is due to O2 sensor or if the car needs new cats or what. Would just like to troubleshoot it as far as possible before we blow any cash. I figure finding the proper location for this wire is a good place to start.
Any help is appreciated. I am not familiar with this car at all.