before i got my custom exhaust setup my 99 rx was making a rattling noise whenever the engine is on. i learned to live with this noise, but when i reset my battery, for performance reasons, a check engine light will come on after a couple of miles. Usually the P0171. i would then reset my battery again and the code wouldnt pop up again.
during my exhaust install i mentioned the rattling noise to the guy making my system and he said he also noticed the noise when i pulled up on the lift. when he looked at the area where the noise was coming from he saw that my precat was cracked. for a quick fix he welded it shut and the rattling went away, but he did tell me to have it replaced.
i reseted my battery again a couple of days ago (for the new exhaust) and now the check engine light came on.
i just now disconnected the pos and neg on the battery and going to leave it unpluged the whole night. hopefully the ecu will overlook the problem like the past.
can i just use a universal free flow cat as my precat or do i have go to the lexus dealership? Or is there a oem toyota precat part that will fit on the rx300, but is really meant for a highlander or camry?


thanks!!!!

Exhaust plumbing may be slightly different between RX and Camry. I believe federal emission warranty covers cats for 8 years, are you still under that warranty or is it just a California thing?

i have no warranty, but now i kinda wish i live in california.

is the precat the same as a highlander or sienna?

1MZFE engine should be similar to the Highlander as they had similar power in their engines, but as TunedRX300 mentioned Camry is slightly different.

I also found myself welding parts here and there on the exhaust before I did those downpipe modifications. Some Solara owners, that also use a 1MZFE on the 3.0 model, do not have OEM precats. Just depended on what part of the country the vehicle was sold in. However, I am 99.9% sure all OEM RX300s had them in North America.

can i just change change my broken precat with a pipe or do i have to do both? also if i do this do i have to change my cat to a aftermarket cat or can i just keep my stock cat?

I am going to put legalities aside as I had a similar issue down here when my one of my precats bit the dust and the only solution I had down here was to put straight pipe (it only made .1 difference in the 1/4 mile) except for the Magnaflow cat I have on there now.

If you put straight pipe on the precats, the stock OEM cat is not sufficient to pass emissions test (at least not where I live), but if you get one of the Magnaflow cats like I have (see page 3 on my site below), these are 3 way cats and will do the job.

i think ima go buy a toyota precat and replace it myself. it looks like it might cost more if i make both the precats a pipe and putting on a magnaflow cat.

found the one i need for $264.95. it looks like its just bolts so i could probably just do it myself.

http://replacement.car-stuff.com/par...howdc=true#top