Have to Laugh at this one

I purchased a used 2007 Prius with 130K on it a little over a year ago. Been doing great except for a middle aged battery I replaced with NPB 6 months ago. No codes and still worked OK, just on the tired side and rated at 60% by Dr Prius at purchase. This was factored into the purchase price, so a planned upgrade.

A couple of weeks ago it flagged the P0420 code. Yikes... I'm 3 months away from having to smog cert in Cali, so not good. I did some data logging and the rear O2 just didn't look right. It would sometimes, randomly, straight-line at around .7v when the motor was off. And sometimes show 0v when the engine was on for around 30 sec. This didn't happen real often and I happened to catch it on one of 4 logs I recorded. So for sure the rear sensor was worth pulling and testing.

When I pulled the O2 there was a strange bulbous wad of tape near the connector in the car interior, which was apparently a repair with about half a roll of electrical tape. It took me 20 minutes of heating and unwrapping the tape to see was under there. I took my time because I did want to see what lurked under the tape. What I found was comical, as shown in the pic.

Pretty janky huh? The good news is a new Denso O2 and the car is fine again. Thought you all would get a kick out of this, and I guess I dodged an expensive bullet.

 

I think the picture doesn't do it justice. There are big globs of solder and lots of areas with no solder. I'm surprised it lasted a year without throwing a code. Each wire had a huge amount of tape and the whole thing was then wrapped with a ridiculous amount of tape. It looked like the bulb used to pump up a blood pressure cuff. I thought maybe the result of a repair after a stolen cat, but I verified the cat was OEM during pre-inspection on a lift which I verified myself, so unless they found another used cat (illegal here) I'm not sure what to think other than maybe the original O2 got snagged on something and ripped the wires. That still makes no sense since the rear O2 is not very expensive. Just the labor of that much tape wrapping would exceed the cost of a new O2. People do weird things sometimes.

 

Good question. Interesting to note the denso O2 that was repaired was the right part number for the Prius, so a strange case. I'm guessing something snagged the O2 wire and it separated and the guy decided to repair instead of buying a $50 part. I'll bet that if the repair was done with even a modicum of craftsmanship it would have lasted for many years. Either that, or he should have used an entire roll of electrical tape instead of half a roll