Help me figure out this issue

So, I have a 2006 V6 4x4 TRD Off-Road. Stock as far as the power train goes.

I've always had this loud ticking sound that I swore was an exhaust leak. Very pronounced when I'm at a drive through and it's echoing off the walls. Noticeable at low RPM and grows a bit as I rev it but noise is drowned out as the RPMs come up.

I also get a rough idle sometimes. More so when it's cold. Goes away shortly after.

Lately, I throw a P0430 (Catalyst System Efficiency Below Threshold) code on startup. It then goes away. This kind of confirmed my exhaust leak.

I put the truck on a lift and checked for the leak but couldn't find it. I thought for sure it was going to be the headers, but I checked it and I couldn't find a leak (no black soot, no bubbles with spray test). I even did a smoke test and couldn't find a leak anywhere.

Then I got the other day I got a random P0302 code (Cyl 2 misfire). That code went away after a bit.

May each of the 3 issues is unrelated...maybe related...not sure. I have swapped with new plugs before. I've done Seafoam too.

Main issue I'm concerned about is the ticking. Anything else it could be if not an exhaust leak (I still think it's an exhaust leak though...sounds like one - just can't find the leak).

Any suggestions appreciated. Thanks!

 

Can you post a video of the sound you’re talking about? Mine has a ticking at idle as well but it has been there for 72k miles of my ownership and no issues. From what I understand it’s normal for these engines but yours might be different?

 

The 4.0L does tick, some are noisier than others (post a video maybe so we can hear it).

Not sure how you would get a P0430 at startup because the catalyst monitor runs when driving at a steady speed.

As for the misfire what do the plugs look like? Have they ever been done? (should be done at 30k intervals if they are stock copper).