I hear exhaust noise approximately from below my seat last month or so. Noise get worse last week. I started car in this cold morning to find if smoke will come from somewhere in exhaust line. Obvious suspect was cat as it is just under my seat. And I saw smoke coming from mid of cat when car started. So not from cat front or back flange. After a few minutes water start dripping from mid of cat approximately. How much I know it should not be any water dripping from there? My question is if I need some special cat because my Acura 2003 tl is type S. Do anyone know about something that can be fixed at cat to stop leak? My line of thinking is if cat get hole from rust plugging hole will not help in long run as will soon hole open somewhere else at cat.

 

You can always get a magnaflow high flow direct fit cat for less than $300 worse case scenario.

 

Well I said wrong. I checked this morning too. It was 25F for difference of 35F yesterday and I saw smoke going out of rear flange. I put finger there, as "Eric the car guy" recommended and I felt how air is pouring out of rear flange. I usually check everything multiple times, so it was right to do this time again. Probably will need gasket and new screws. Old are rusted. I guess gasket should look like triangle. https://mufflerexpress.com/products/...RoCxKoQAvD_BwE
Do not understand why some are selling some circular rings.
https://www.ebay.com/i/292801194480?chn=ps

 

Well some say one side gasket is ring. https://www.ebay.com/itm/1999-2003-A...-/264154926969

 

OEM setup uses a donut gasket that gets placed into a circular groove. It gets crushed against the flange it is tightened against. Some people don't like these types, so there are flange shaped gaskets that you can use instead. I'd suggest getting the Walker 31383 exhaust gasket for the rear flange of the cat. This gasket fits between the cat and the long exhaust pipe.

 

^^^ Thanks for clearing that. I went to NAPA and they had original gasket for 13$. Front and rear are obviously not same. Went to O'Reilys and they had in stock something same in shape like what you recommend for 5$. I think it is universal flange gasket. So I bought it. Will not do it till end of week, busy at job, but will let you know what I did.

 

Did job like promised. Had to slam old bolts a dose times to get them out. Went to Acura dealer to bring that special self locking nuts. One cost 2$ and they give me 3 bolts free. So 3 nuts and 3 bolts for 6$. Opened just one bolt of heat shield. It give me enough space to put new bolts. Third old bolt at top I didn't remove as his nut hold still always. Tried to slam 5-6 times to kick it out didn't work. Whenever it will rust trough it is easy to kick it out and put new bolt. It toke me only 1,5 hours to do this. Easy. Obviously didn't use new gasket as didn't pull out 3. bolt. Car is quiet now so no need for gasket. Put at bolts and between flanges (how much space allowed) a lot of nickel antiseize.