2012-2014 1GR-FE (V-6) Pinging (Spark Knock Noise)

Let me know how it goes . I did go an independent local owned shop where the owner is a master Toyota tech who open up his own shop. I had him check it out
He used a scope to track down the noise
Traced it down to the driver side cat.He
Had on noise before the cat only noise from the cat . He owns 08 4 runner similar noise he’s not considered about it
He has seen a lot of the 4.0 with this noise he said the latter 4.0 seem to be louder than the earlier 4.0 s he told me he could replace cat if I wanted but he said cost is not really worth it . He did not find anything to be considered about