The Xterra needed a new catalytic converter so I took it in to Master Muffler (my usual mechanic doesn't do exhaust welding) because they were highly recommended and had good reviews online. I was quoted $400 over the phone for the job, which seemed competitive to other places I called and cheaper than the dealership (not surprising). I took the vehicle in and before it was even pulled into the shop the price had mushroomed to $700+. Alright, maybe someone looked up the wrong part or didn't account for labor, mistakes happen and I need the work done to register the car.
When I get the car back it sounds like someone drilled holes in the muffler and the check engine light comes back on as soon as the computer resets itself. Now it's throwing a code for a bad O2 sensor - specifically the one right next to the catalytic converter that they welded on. The repair has a 2 year warranty, so I take it back.
They call me with a story about how they aren't responsible for the sensor and "there is no way to tell when it went bad, it was probably bad before it came in." When I told the guy that the car was not showing any O2 sensor codes before they worked on it, he said that the vehicle is "not capable" of showing more than one code at a time - which is an absolute lie for an OBDII vehicle, I've personally seen multiple codes at once. He wanted nearly $400 to replace the O2 sensor but at least he replaced the exhaust gaskets under warranty. Since it was Saturday and I'm now in a bind to get it registered by month's end, he has me over a barrel.
I'm now $1,100 into a $400 estimated repair. The Check Engine warning stayed off for a whole day and is now back with the exact same code as it had before. Now I'm calling in favors with my usual shop that is booked up to pull all this apart and take a look at what exactly these clowns have done to my vehicle.