PerpLexusd

So I was having some problems with lack of power in my car and tracked it down to the cats being clogged I pulled them off and one was completely destroyed inside. I start shopping around for a new one and they're like $200. I did what any logical person would do and decided to just get rid of them. Here's what I did...

To take off the catalytic converters there's a good how to on lexls.com
http://www.lexls.com/tutorials/exhaust/fpipe.html

First off all the material
2 bad catalytic converters
2 2 1/2 ID 18" tailpipes (I got mine from autozone for $7 each)
Metal cut off discs (I went through 2 on the angle grinder)
Welder
Grinding wheel
Exhaust gaskets



First you're going to cut off the brackets from the cats, you can buy them on lextreme for like $60 if you want, but I figured I have a free set so I used those.



After you got them off grind them down so they look nice and shiny, if you notice the two brackets on the bottom have rings inside from the excess tube you want to keep at least two. But you want to keep the ones from the 2-hole brackets.



After you have the brackets cut off and ground down, you're going to get your tailpipe pieces and grind off the galvanization on one end. The pipes I got have one flared end, that's the first side I used



Now get the 3-hole bracket and put the pipe in it, the bracket has to be up a little about 1/4"



Put a couple tack welds on (something breakable in case the they're not in the right spot)



Now the cats are 10" end to end but just to be safe I cut the pipes a little long about 12"



Do a quick test fit to make sure it'll fit flush on the manifold



This is where my camera died, but next you're going make sure it fits then cut it to the right size, 10" next you grind off the galvanization from the tips again. Do another test fit to make sure everything is going to fit.



Mark on the tabs where the brackets are so you can tack it together in the right position.

This is where those rings from earlier come in. I think the metal from the cats were thicker then the new pipes, so the pipes fit perfectly inside the brackets with the rings in them. Tack the brackets together and do one last test fit



After everything is test fitted, go ahead and weld it together



And you're finished product



You can stop there and bolt it on or you can clean up the welds and paint if you want. I wanted to



Then bolt it up and enjoy your easier breathing Lexus

OKSTANCE

How is the exahust clearance under the car? same as stock or tucked up?

billydpowe

iTrader: (1)

does it affect your 02 sensors?

oldyota

Nice write up i was going to do this anyway without bad cats. Did you see/ hear results

PerpLexusd

Same as stock I made the the same length as the catalytic converters


I'm not sure about the o2 sensors my cel has been on since I got rid of my egr, I haven't checked the codes yet to see if anything new has popped up.


And it sounds a little deeper but not much of a difference, from what I understand these cats are fairly unrestrictive so I don't think you get much gain from deleting them if they're still working

Lavrishevo

iTrader: (1)

You will have code 420 and 430 stuck on unless you get the 02 simulators. Considering it is bad for the environment and very minimal HP gains, I am a fan of just replacing failed converters with aftermarket ones. I'm not a tree huger but driving behind a car with no cats is...

Dranom

iTrader: (7)

Hows the smell?

PerpLexusd

I just checked my codes and I don't have any new codes arising due to them being gone, I would have got new ones also but I didn't have $$$ to spend on universal ones that would be more restrictive and I couldn't find my suitcase of gold bars to get an Oem replacement so I opted for the cheap route and got rid of them

I don't know, I haven't got behind the car to smell it, but from inside I haven't noticed anything

LScowboyLS

LS cats tend to be extremely reliable, and the car has more power and reliability with them than without them.

If this were a good plan, mine would have been off long ago.

It's not.

IwantLS400

I had the Cat Eff code and it came and went...I got tired of clearing the light so i threw in some FJcruiser cats i had sitting around and had the resonators removed and it sounds perfect and runs great. Cant hear it really. when your in it you hear a little bit. A good cat wont kill power. A failed cat will.

PerpLexusd

I agree that they are reliable and efficient ,mine lasted 20 years, but sadly they still do fail at some point and mine did. But the car having more power with them isn't true, although without them the power gain is insignificant it still has a slight power gain.

It's kind of like having a napkin over your mouth while breathing, no matter how much it air it flows you're going to breathe better without it.


I am in no way saying this is a performance mod, rather an alternate to replacing expensive damaged parts

dashan

Can you just gut the Cat, put a tail pipe inside of the cat, and then put the cat back on the car?

PerpLexusd

yeah probably but then you can't recycle them and get your money back

timmy0tool

iTrader: (7)

i would have started the car with open downpipes like that and recorded a video for kicks! good work on the craftsmanship. clean welds!

ThomasGS4

iTrader: (19)

So, I'm guessing you have no plans of passing the state inspection legally?