Hello, looks like my Catalytic Converter is clogged. Anyone know which one to buy off of RA for 03GS300 ? P0430 code.

 

Which bank is indicated in the P0430 code, if any?

It's often not a clogged cat but instead a failing O2 sensor, which are much cheaper to replace.

As for the cats, your car has 3 - two are located in the exhaust manifold and there's a third after the exhausts from bank 1 and 2 combine. Any way you look at it, by this point in time most of the exhaust has been rusted together and you'll need someone experienced with exhaust work to properly hack off the old stuff and install the new one with the proper flanges.

 

Bank 2
https://www.rockauto.com/en/moreinfo...416596&jsn=344
i think this one will work?
Would the O2 sensor cause it to hesitate with throttle response?

 

That looks like the correct part. And yes, a bad O2 sensor could cause that...it its throwing faulty readings to the ECU everything related to how the engine runs is on the table.

 

Those are not expensive. I should get both upstream and downstream. Easy to change those?

 

The P0430 code does not mean that it is clogged. This means that it has a loss efficiency.
It simply does not process exhaust gases with the required efficiency, but passes them by.
It will not harm your car in any way other than Check Engine light.

 

A truely clogged cat convertor can be like putting a potato over the exhaust pipe. Causing excessive back pressure will cause the car to bog down.

A cat code like said only means it is functioning below 95% efficiency. So at 94% throws a code.

A bad o2 sensor causes the car to use excess fuel, often times leading to black soot at the exhaust tip. If soot has built up in the pipe it's probably in the honeycombs of the cat convertor. Too much build up can be like too much soot in a chimney on a house.

 

That is exactly what I have. "can be like putting a potato over the exhaust pipe" Complete back pressure. It will start and idle but bogs down bad when I give it gas. Ordered the cats from RA and will have Midas install them. Thank you everyone. I was hoping to move to leather and paint, but mechanical keeps haunting me. Alternator Saturday and now cats. Oh boy.

 

Update on my cat issue. Got the cats installed today at Midas. Same issue. Midas showed me my original cats and guess what. ZERO honeycomb material in both. Not sure how I passed inspection. All that honeycomb material is now somewhere in the exhaust past the first 2 cats. They are cutting out my 3rd cat and straight piping that. Hoping that will be where all the debris from the cats will be. Its not monitored, I am pretty sure. In Texas no one gets under the car for inspections. Will know tomorrow what the result was. Find the debris game.

 

If all of the honeycomb has left the first two they likely clogged the last one.

Thanks for the update(s).

 

Self-disappearing cats

 

The Cheshire catalytic converter, throws a code then disappears for good!

All jokes aside, Bykfixer is probably right.

 

Fixed now. Midas cut out 2nd cat and had to clean debris all the way through exhaust system. Hindsight being 20/20, I wish I would have put the Tanabe Medallion Touring on it. But I am back in action and it is driving and performing perfectly. Back in GS land, WOO HOO!

 

I have developed a heat shield rattle after the cats. Annoying but still drives fine. Looks like I will order the Tanabe exhaust. That will basically be all new exhaust from cats all the way back. Is the heat shield necessary on the stock exhaust? Aftermarket of course has no heat shields.

 

Surprised MIDAS does that kind of work! (Straight pipe)