Hi all!

I have a 06 IS350 with 169k on the clock. I recently got the C1201 and P0430 codes with a VSC and CEL. The local shop that I was getting tires replaced (who also do general maintenance) told me that it was probably due to a catalytic converter and that I should call/take it to an exhaust shop. I read up on the forums and found that it isn't usually the catalytic converted but usually an exhaust leak or an O2 sensor. With that being said I did the following tests/prior maintenance and was hoping someone would be able to give a little more direction before i make the plug for new catalytic converter.

125k miles --> replaced all plugs
February 2020 --> replaced engine air filter
O2 sensors are all reading correctly
Cats have the same flowing temperature
I do have a slight sulfur smell when really accelerating (did it even after the code and car accelerated completely normal)

I am a little unsure of the next steps as to if it best to just take the plunge and replace both banks of catalytic converters near the engine or if there is another area I should look. Car does have a tanabe axle back that was installed about 7 years ago and has been issue free.

Thanks in advance for any and all help!!!!

 

If it's the O2 sensor, any decent shop with scanner can tell you on the spot if it's an O2 sensor. If you smell sulfur, than it could possibly be CATs or yes, an exhaust leak. I would take it to a exhaust shop, if it does turn out to be an exhaust leak they should be able to fix it without major expense. Years ago I owned a 76 Mercedes 280, the muffler had a hole in it and some of the exhaust pipes had rusted out. Midas wanted to change the whole thing for over $200 (a lot of money for young student in the 90's), I found a small muffler shop in a little crappy city in LA County, the guy did the whole thing for $60. He replaced the muffler and cut out the rusted piping and welded new piping in its place

 

Thanks! shops are closed where I live due to it being later in the day but I will take it to one first thing.

 

Let us know how it goes!

 

So took it to a local exhaust shop and they said that it had a leak on the midpipe flange that was closest to the engine. Total cost was $100 and I had to clear the codes manually but so far I have driven about 15 miles and the issue seems to have been resolved for now. Probably will go ahead and replace the catalytic converter’s in the next year or so just to be safe

 

Update: after 3-4 drive cycles the code came back on. if anybody could indicate which cat/part is needed to correctly rectify this that would be greatly appreciated. I know there is the manifold with the cats in them and a Y pipe with cat(s) in them. Any diagram would be extremely helpful!


first picture indicates the exhaust manifold with the red circle being the upstream O2 sensor and blue being primary cat

Second picture Indicates downstream O2 in green, and y-pipe/3 way cats circled in purple

can anybody confirm my crayon drawings lol