P0430 - Replace the Cat

[tabrown11]

Hey All,

I have a 2001 QX4 with approx 165k miles on it. I recently replaced my O2 sensors [was getting CEL's for those] and a week later I am getting the P0430 code. From research online, I know that it is the Driver's side Cat triggering the code; however, I want to confirm a few things before taking this on myself:

1) Do I need to replace the upper or lower Cat? [I am thinking the upper, b/c of where the O2 sensors are located; but want to confirm]
2) Where can I find good quality for the price for a Cat, shopping online?
3) Where can I find a good "How-To" on replacing a Cat?

Thanks for the time and help!

[centralcoaster33]

I think you want to replace the cat that is located between the two sensors.
Online seems to have the best prices for Cats, but you'll be buying a bolt on and that costs more than a universal. An exhaust shop can get the universal for cheap and weld it in place. So, I'd get a quote from a shop or two and compare that to buying a bolt on and putting it on yourself (time, tools, getting dirty, those have a value you can make up for yourself).
The FSM will have all the necessary data on the exhaust and you can get that from the Service Manuals link at the top of this page. But, the exhaust system is very simple. If you've done your sensors, then you're already familiar with it. Just get the clearance you need to get underneath safely (use jack stands and wheel blocks in addition to a floor jack). Get out the ol' PB Blaster and soak the nuts and bolts on the cat to be removed. Unbolt the old one and bolt on the new one. It's pretty easy, but someone may have made a youtube video. I don't have one to recommend.

I just went through all of this with a friend's 4Runner. We did the sensors first, hoping that would be good enough, but the cat was actually no longer working. We are in CA and CARB has created an expensive situation for CAT replacement. We ended up having a shop weld in a universal cat with CARB OE stamp or something on it somewhere. Don't worry about any of that if you're not in CA.

[RR425]

Had the same thing on my 01 QX4. Check engine light was on and could not pass emissions. Changed both downstream O2 sensors and both catalytic converters (the ones between the sensors).

I got the Walker cats from Amazon. Search "Walker 81754 CalCat Catalytic Converter" and "Walker 81753". They're about $250 a piece but my check engine light is gone now and passed emissions.

[RR425]

3) Where can I find a good "How-To" on replacing a Cat?
==================================

It is not difficult, if you have a garage and some tools. The big pain for me was rusted screws. I had to saw off the heat shields from the old cats with a small metal saw to get to the screws that hold the cat (need a long extension with a socket wrench). Also had to saw off the old rusted screws near the other downstream cat where it connects to the exhaust (drill a hole and insert new screws). A pain dealing with rusty screws but other than that it is very straight forward and doable. Just unscrew the old cat and put the new one on.

[atraudes]

I'd read through this thread if you haven't already. Good luck!

replacing-catalytic-converter-not-much- ... 09397.html