Replacing the cat is quite easy. Just dont expect to reuse the bolts. Use a breaker bar for leverage and break bolts or heat bolts to red hot . Heating them is the best method as it breaks the rust bond and ensures entire bolt comes out in one piece. The bolt heads tend to shrink so avoid star shaped sockets and use sockets that are 1mm smaller if you get in trouble.

Parts
-two flange gaskets(part no. 31540) $3 each

-8 * washers were required(4 m10; 4 for 14mm head bolt)
-2*m10 by 35mm bolt( ie 17 mm head, length of thread part is 35mm, thread diameter is 10mm)
-4 locking washer(2*m10 and 2 for the 14mm head bolts)
-2*17mm nuts
-2*14mm nuts(1.5 inches long)(they dont include head in length measure)
-2*14mm bolts(I'm referring to head width. are these m8's?)
-new catalytic converter. direct fit means it fits on without any modifications.
it should be 12.5 inches in length. I bought Bosal part no. 99-852 $99 cdn. Napa always has the highest price for same part no. you dont need a heat shield or a protection plate on bottom. the car has a heat shield above cat.

(the original 17 mm bolt had a thread length of 25mm, 10 mm diameter. it screwed into cat conv flange. stuck out a quarter of an inch . part that stuck out had its threads eroded away. It obviously had no nut)

note: the length of original cat is 1/16 inch less than 12.5 inches but this is due to flange being eroded.
note: normal steel bolts are fine. you dont need stainless steel. use antiseize.

Tools

-14 and 17 mm open end wrench
-14 and 17 mm socket wrench(6 sided socket , not star)
-13 and 16 mm socket if bolt heads are rounded
-hammer(optional)
-MAPP gas or propane or oxy acet torch(optional)(mapp much better than propane)
-jack to hold up pipe going to exhaust manifold(not sure if you need this)
-WD40
-antiseize crayon

Procedure

1. Remove the bottom protection plate by breaking the 4 by 10mm bolts. they break easy with small socket wrench.

2. You may need to support the pipe going to exhaust manifold. Remove the two 17mm bolts. They do not have nuts. They screw into cat flange. Only the cat flange has threads. The hanger and pipe flange dont have threads. Your new cat likely wont have threaded holes so you need nuts.

3.Remove the two 14 mm bolts on the downstream side of cat and remove old cat.

4.clean off the flanges with wire brush.

5.Put the two 17mm bolts through hanger and pipe flange. Be sure to put anitseize compound on bolts. use the bolts to hang the gasket. Put new cat in place and tighten 17mm nuts.

6. install the other side of cat with the 14 mm bolts. Dont forget washers as the holes in flanges are too big for bolt heads. Locking washers are also important.

7.Torque to around 35 lbs. Check tightness after having driven for awhile.

Pictures:

New catalytic converter:

old gasket and locking washer

17mm thread in old cat flange

cat bottom protector

old cat with old 17mm bolts(note how eroded the ends are that were sticking out)

Modified by vancouverbc at 7:05 PM 11/26/2008

Modified by vancouverbc at 7:10 PM 11/26/2008

Modified by vancouverbc at 7:29 PM 11/26/2008

Modified by vancouverbc at 12:47 PM 12/7/2008

Modified by vancouverbc at 8:17 PM 12/7/2008

Modified by vancouverbc at 3:10 AM 4/5/2009