royalspade

Newbie here, but a long time lurker. I have a '01 GS430 that has been recently diagnosed with clogged/bad catalytic converters by a Lexus dealership. They advised me to replace it with OEM parts, but a single cat alone cost $1,500! I'm talking about the two cats that come after my headers/exhaust manifold on both sides. I'm wondering if any of you guys can point me to the right direction as regards to a trusted and direct fit aftermarket catalytic converter?

sivikvtec

Check for exhaust leaks first. See if this makes the CEL go away.

tmf2004

iTrader: (15)

check ebay for stock or aftermarket replacements.... That price is crazy...

angus

iTrader: (4)

Or get aftermarket high flow cats.

royalspade

I've considered that and we looked closely into it, found no leaks.

I found a Magnaflow one... anybody reading this have this on their car? http://www.andysautosport.com/produc...ow__49909.html

Ahheck01

iTrader: (2)

I'm curious - would one see a performance gain from a high-flow cat and otherwise stock exhaust system? What are the other key bottlenecks, in order?

angus

iTrader: (4)

You will gain some from the high flow cats alone - if you don't want to make noise then the rest of the system will be tough.

If you don't mind noise you can get a catback system and the Y-pipe from megan for the SC430 fits with a small extension.

You could also do the Y pipe and keep the stock catback.

angus

iTrader: (4)

The Magnaflow (or other "jobber" cats) are garbage, there's a reason they are so cheap - I've seen them melt and crack lots.

Get a good set of spiral metal core cats and you'll be set, I have had those on my GS for years.

PM me if you need help, I'm in Canada too

MattyG

I have the Magnaflows on my 02 GS430. Ran into the same problem as you, my right cat got clogged. Mine have been on for a year and a half and no problems so far (fingers crossed).

I didn't notice any real performance gain.

royalspade

I already pulled the trigger on the Magnaflow one before I saw your PM lol

Awesome, fingers crossed mine lasts too haha. I don't mind not having any performance gain.

DMPesso

I hope you realize you just wasted money. I am surprised no one else said this since I must have said this myself at least 7 times to different people. 99.99% of the time its an exhaust leak or most likely the O2 sensors. The cats rarely ever go bad on these cars, they are built to last, hence why they cost $1500 and an american car has cats that costs $200 you can assume the diffference in price is for a reason. Also, non OEM cats will make the car lose power as it requires the back pressure the CATS cause because it all runs together to form a constant flow of pressure to deliver power to the car. Unless your changing the entire exhaust setup you might notice a loss in power from the NON-OEM cats. Change your O2 sensors first.

royalspade

I should have mentioned this before, my GS has noticeable power loss and feels sluggish. I have an (Ebay) aftermarket exhaust. Could an exhaust leak and or a bad sensor be the cause of the sluggish-ness and power loss?

iamkhanz

If u got the "oem" version of the magnaflows u should be okay these come with double the metals that remove the CO and NOx and all. They are the magnaflow cat line that are California emissions approved.. so should last.

How many miles does ur gs430 have? Depending on the codes it's throwing may be a good idea to change all the O2 sensors..from my experiences once one of those goes bad all if them go bad. There's some decent deals in denso oem o2 sensors..

angus

iTrader: (4)

You would also hear if you had a leak.

If you feel a power loss - look through your cats with a light and see if they are clogged.

DMPesso

do you have any check engine lights? the O2 sensors can DEFINITELY make the car sluggish! but 90% of the time when an O2 sensor is bad it will throw a CEL.. When did you notice the power loss? This GS430 is designed very uniquely, depending on what kind of aftermarket exhaust you put on and what you removed in the process that could also be the reason for your power loss as like i said before the performance of the car depends alot on the back pressure the exhaust provides.