brybo86

Was going downhill at about 40mph and had to slam on brakes at like 90% force.
CEL came on P0430 bank 2

​​​​​​ Coincidence?

jaxscuby

cat inefficiency bank 2..hhmm..it wouldn't hurt to take a look at the rear O2 sensor..check connector(s)

brybo86

I finally got around to checking into this and I think I found the culprit...
With the car running I could feel a decent amount of air coming through this crack here
The broken gasket is on the right at the junction just after the catalytic converter there, notice the oxygen sensor immediately after it
this is on the passenger side of engine
I will probably need to take this to a muffler shop as those bolts are rusted beyond belief

jaaa

You don't even have to take off the cats. Just buff down the surface on the flanges and take the rust off all the way around. Then while it is cold, patch the holes with VersaChem Muffler Weld(repair and sealer). Works like a champ, though you have to let it set up for 12 hours or so. I patched mine after I got a 420 code, and it fixed it right up. Can of it costs a whole $7 or so.

Amskeptic

Then again, you could dremel the bolt heads off, separate the flanges, install new gaskets and bolts/nuts and enjoy another 25 years of reliable quiet Lexus . . .
Colin

jaaa

Tried that already and it won't work. After I cut off the bolts on my car, cleaned off the flanges and reassembled with new gaskets, it leaked even more. The flanges on the Y pipe side of the flange had so much corrosion/rust that you would have to grind down the whole flange a 1/4 inch to make it flat again. The product I recommended to him will work and he won't have to separate the flanges.

brybo86

first pic is 12hrs after application of the versachem muffler weld in the black tub
second pic is 36hrs later after driving for 20 Mins,
I cleared the CEL and it was off for the 20 mins of driving.
stuff looked like it bubbled but it was rock hard to the push of a finger nail