supergirl79

This all started when I originally went in for a smog test and failed...many repairs and many tries later, I ended up replacing the engine (used), and also have a new catalytic converter. Before replacing the engine, it took 1,000 miles of driving before I had enough monitors ready to test...my cat and evap never set, but the O2 heater monitor finally set and then I got a check engine light, leading to the newer engine. Now, after almost 600 miles, I nearly screamed when the CEL came on today...I was hoping it was my gas cap, but when I took it to my mechanic he hooked up his obd scanner and it showed a fault with the O2 sensor, which was not setting this time (since the engine replacement). The thing is, he tested the wire from the sensor and it reads just fine...the numbers fluctuate just as they are supposed to, but when he hooks the scanner up under the dash, the scanner reads "0" for the O2 sensor. He said it could be the wire, but is more than likely the computer. I have looked all over the internet for another option, because I have already spent WAY too much money fixing this car already, and more than one forum suggested replacing the wire. Someone with a Ford minivan had a similar problem and he was told to replace a fuse, and that fuse would also control the cig. lighter. My accessory port went out since my last smog check...would this be an indication of a faulty wire vs. a faulty computer? Also...have read that jump starting cars or having yours jumped can short the computer...is this true? I have jumped a few cars since my last smog check and when my battery went out last August I had to jump it a few times (shop wasn't open when I got off work or before I had to go back the next day). I admit I haven't checked the fuse for the access. port...should probably do that, but more pressing matters have taken priority. Any help would be appreciated...even if it's bad news...just need some extra opinions and assessments of the situation before I go dropping another $500+ for a computer I may not need...as it is, I'll be paying my repair bill for the rest of my life!

Thank you!