I have the dang "P0420 Catalyst Efficiency BelowThreshold - Bank 1" code.
I'm looking for more knowledge on this issue... to see if anyone has a definite answer on this piece.

Seems like the best option is to get the ECU reset, if I can get past the Diagnositic fee. A bonus would be to get the MAF replaced before I go there, and reclaim some MPG.

From my research I know this:

• Option 1 - Update the ECU at the stealership. Cost = $80.
  -- Seems like most people have success with this one. However, I called and they said no matter who pulls the code, they still have to charge me the $100 diagnostic fee... then they will make a "determination" and determine to charge me my first-born. How do I get past the diagnostic fee, and just get the ECU flash done?
• Option 2 - Replace the pre-cat, e.g. replace the y-pipe. Cost = $100 or so, depending on which company you buy it from.
  -- I've read a few people with the y-pipe mod/option, and they are saying that they still have the same code. Seems like this won't fix it, although a fun "repair" to have.
• Option 3 - Replace the MAF. Cost = $88-$100.
  -- Mixed results, most of what I've read is that ppl have to get the ECU reset anyway.
• Option 4 - Replace the main Cat. Cost = $100+.
  -- Again, no consensus. Most ppl say that this isn't the problem since the code refers to Bank 1, which is in the pre-cat.
• Option 5 - Replace both Bank 1 O2 sensors. Cost = $170.
  -- No consensus. Some say that they no longer have a code, some say they replaced all 4 sensors, B1 and B2, with the same error code.

I have an '02 and I'm at 156k, so definitely out of the 8/80k range.

Changing the Y-pipe, Cat, or O2 sensors seem like chasing the dragon... so, I would only do those if the first two didn't work.

I want to get this thing fixed in the next two weeks, and definitely done want to have to chase it down for much longer than that.