Changed the cat. converter and brake pads today. There is still exhaust rattling, so I still don't know what's the cause. I'm pretty sure I don't have any heatshields:

It's evil

 

So I changed the cat but recently the car has been stalling when I am coming to a stop. The RPMS drop pretty low then it cuts out. This doesnt happen at idle though.

Thoughts?
EGR is clogged to ish, but I have a new cat, knock sensor, IACV from two or three years ago, I havent cleaned the filter in awhile though :/ kind of scary since my siblings drive it time to time and don't know it as well as I do

 

had some fun AWWWWW YEAHHHHH

 

 

Indeed sir

 

So i got a problem...

Exhaust rattling still exists even after I changed the cat. converter, and checked for any heatshields - I have none.

So I do recall when I changed the header - engine block gasket it went away for one day then came back.

I remember I snapped off one of the studs on the header, but didn't think it was a big deal. However, I now believe this is the source of the rattling since the Y-pipe is not completely held up against the header. Here is a picture of the bolts:

http://www.ebay.com/itm/STAINLESS-STEEL-MANIFOLD-HEADER-EXHAUST-95-99-NISSAN-MAXIMA-3-0L-V6-A32-VQ30DE-/170730439344?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AMaxima&vxp=mtr&hash=item27c053c2b0#ht_3236wt_1219
problem is those bolts are welded to the header. I do not want to buy a new header, so do you guys I think I can drill through that bolt and slip on a new one so I can attach a nut to the new bolt? i think it is stainless steel, I do have drill bits...

thinking about making a small bore first, then progressively making bigger ones. In addition I saw some vids for drilling through stainless steel. First you make a small indentation with the drill bit, then put on some jelly stuff to keep the temp down when you drill it again to make the hole

This sound is the only thing making the car imperfect. Comments, suggestions?