joedecker4

92 Lexus SC400.... Today I went to replace the main catalytic converter on the drivers side ... I got the bottom unbolted, but the problem came when I went to take apart the 3 bolts on the top. They are VERY difficult to get to, I have tried EVERY tool possible and still can't get then. I went and got a saw-zall type of cutter to cut the bolts with the plan of replacing them. I got one cut off after an hour of trying to manuever the saw end to the right place. I now have multiple cuts in the catalytic converter With in inability to access the other two bolts.
My question is, if I take off my front drivers side tire, and the well inside, will I have at least partial access to the top of the catalytic converter ?? Any insight or tips would be GREAT appreciated! Thank you!!

joedecker4

Anyone know how to access the top bolts besides from underneath??

1siksc

iTrader: (8)

Your best bet would be to ask O.L.T. or find someone that has put aftermarket exhaust on a sc400. Wish I could help, but thats the best i got!
https://www.clublexus.com/forums/search.php

Neucorp

iTrader: (1)

Try an impact wrench with a 12 inch extension plus a 4 inch extension plus a deep socket.

alanchad

iTrader: (1)

According to the repair manual:

Remove the 4 bolts holding the pipe support bracket to the transmission.

Remove the 4 bolts and nuts holding the catalytic converters to the front exhaust pipe. Remove the support bracket.

Disconnect the front exhaust pipe from the catalytic converter, and remove the 2 gaskets.

Remove the 3 nuts, converter, and gaskets. Remove the 2 catalytic converters.

Hope this helps.

Alan

neanderthl

Wow sounds like a huge pain, man. It would be a pain to do this, but it might actually be faster to unbolt the stock exhaust manifold to let it hang down a bit more, and then go at those bolts.

Neucorp

iTrader: (1)

I think that's a good suggestion neanerthl, but I would also caution that the manifold bolts will be quite stubborn as well. Be prepared to replace your manifold gaskets if you go this route.

neanderthl

Hmmm... Good point Neucorp. Good luck and keep us updated. I wish I were closer AZ. We could tag team it and have that cat out in no time.

b1ackhawk

I have done this, you need a semi deep socket like from Snap On, or SK deep well as their sockets are not as deep as craftsman or snap on regular deep wells. You need a deep well to go over the stud, but too deep will cause the back end of the socket to hit the cat on 2 of the 3 studs not allowing you to get the socket over the studs and nuts. The only real way to remove these is from the bottom. These are extremely stubborn nuts to get off, you will need pb blaster and possibly a torch to heat up those nuts. You might even back out your studs when doing this.

I would always advise against using a saws-all to remove things from your car (except perhaps for that terribly rusted exhaust bolt that you can easily replace). Those studs are not so easy to replace, however. If you hacked it with a saws-all than you cut off the end of the stud with the reverse torx head that you would normally use to remove the stud, so good luck with that. You might be able to cross threat a nut on the remaining stud to back out the stud. You will need to go to toyota or lexus to get replacement studs and nuts. Actually the updated studs are a little shorter and allow easier access with a socket. You just made the job 5x harder by using your saws-all instead of the right tools. Next time, think before you whip out your saws-all and start hacking away, find the right tool for the job.

You might want to change out your cat to a Flowmonster type or Magnaflow spun steel type high flow cat that is smaller in diameter than the oem cats, it will give you more room when working under there. Also you could size them accordingly to properly mate some s&s headers for 98+ engines, since the exhaust hangs a little low on our older cars when using those headers.

cbrasian

actually the studs you can replace at any fastener store like here in so cal there's a store I use for picking up studs nuts and bolts called hill co fastener's i'm sure there is one in your area that will have it just make sure you have the proper length pitch and thread and strength and your good to go and take your time and use plenty of wd40 and if it still don't come out you can always heat the bolt or nut to make it a bit easier if you can get heat there

jasonhillp

Had trouble getting to the last bolt on the driver's side today and found this old post. Pictured is what I got to work:

Deep socket + wobble + 3in extension + 7in extension

Cheers!