03 Nissan Murano 2WD Catylitic converter question

[daragon323]

I have an 03 2wd Murano, 106,075 miles on it. A mechanic says I need to replace my catylitic converter, my service engine light is on and is giving P0420 code the B1 catylitic converer to be replaced near the firewall.

I am told this is a $1200+tax job with the part being $900 from the dealer.

Question 1: Is there any other less expensive option to replacing the CAT? additive, cleaning anything?

Question 2: If no, does anyone know of a company that makes an after market converter that won't cost me $900.

Any help at all would be VERY MUCH appreciated!

ThanksDathon