Originally Posted by forthvacav
Since I'm an electrician by trade I believe I'm qualified to tell if the wiring or connector is bad.
No offence meant, but this is microvolt electronics. An electrician is a specialist in electrical, not electronic. They are separate areas with some overlap. An electrician is not usually an expert on micro-volt technology nor on digital technology. You are trained to work on a 20 amp 240 volt sine wave line, but not a 5 miliamp, half volt sensor that uses pulse modulation.
If this were mine, I would obtain a code reader than gives real-time readouts of all the sensors. I would then check those readings at idle and at 2-3K engine speed. I especially would look at all four 02 sensor readings and at all four fuel trim readings.
FYI, if the fuel trim is over 20, combined fast and slow, at idle and it is closer to 10 at 2-3K, you have a vacuum leak. My 2004 was 25-30 at idle and 10-15 at speed. My problem was a vacuum leak. Bank 2 is the front of the car. I used four code readers. The first wouldn't even link. The second read only one code. The third read that same one code. The fourth one read two codes.
The intake manifold gaskets are also prone to leaking air on the Vulcan engine. I found a LOT of people who claimed to be big experts on this subject that were totally off base. They assumed that the part that they usually found was defective was the cause in every case.
I got my information from a couple of TSBs and a white paper written on the subject of fuel trim. The shop that did the work that resulted in the loose vaccum hose wouldn't even diagnose the problem because of the electronics involved. They recommended a shop down the street because the owner there has a college degree in electronic engineering.