BT3100

2002 LS 430 150K miles.
At 120K the check engine light came on. Took to the shop and they found a small crack in the "Y" pipe coming from the primary cats to the secondary cat. Lexus wanted $1200 to replace the whole "Y" pipe. The crack was caused by vibration of the heat sheild. I took it to a muffler shop who fixed the crack (passengers side) for $200. They told me the right side was next. Last month the light was back and I heard an exhaust leak. So I ordered the "Y" pipe with CAT on Ebay for $250. I was planning on have the shop install for $400 more. When it arrived it looked like it may be an easy install. I peeked under the car and saw that there was no welding to be done. The two mainfolds bolt onto the cats and the read side is held in by a clamp (not welded). I tried to crack the bolts on the cats and they unbuttoned easily. At that point I decided to take on the job. Hardest part was pulling up the carpet to disconnect the oxy sensors. Total job took 2 hours.
No more check engine light and the car is quite as new

curiousB

I have the same problem with my 2004. The Y pipe has leaks where the stainless steel heat shield came in contact with the pipe. I think some sort of electrolysis ate a small hole in the pipe.

Can you post who you bought pipe from? OEM is >$1,000. The one I saw on ebay didn't have a heat shield. Did you transfer the heat shield over or just not bother having one?

Do you know what code you had for the CEL? I've been getting P0430... bank 2 converter efficiency...

BT3100

Same code ....the tech at the muffler shop said the heat shield was not needed as there is so much shielding on the undercarriage. He asked if I wanted him to take off the shield the last time. The new pipe has no shield.. search ebay for ls430 catalytic converter. Was 250ish...

BT3100

Here is a link... I am not affliated with this seller but shipping was quick to PA.

http://cgi.ebay.com/ebaymotors/2001-...item3a6207ad8f

curiousB

Looks like it won't fit a 2004 LS430. Seems a bit odd because picture looks the same and the CATs they connect to are the same Part Number...

I think the heat shield isn't to protect the car from the heat, rather to keep the exhaust as hot as possible so the secondary CAT can work properly.

At 8 years old and 110k miles I'm just more interested is getting the CEL to stop popping on every other day....

BT3100

You may want to email that seller and see if he can find one for you.
Good Luck

warminwisc

I talked to a 03 LS owner who replaced the Y pipe at the dealer said it cost 1800 bucks. I have an 04 so thanks for the heads up on future repairs and options! I have 144 k now and plan on running her till she drops.

cjbots

I have the check engine light on with my VSC offf light on. I took it to the dealer, and they say I need a new y pipe they want 1800 for it. Im about to take it to the muffler shop... fml

Kira X

iTrader: (24)

$1,800 is insanely expensive. I have a small exhaust leak on my 05 but no check engine light yet.

Slvr surfr

iTrader: (1)

Have the same crack in my Y-pipe. It is relatively small so i decided to used some exhaust patch tape from AutoZone. For the most part its working as a temporary fix but there is no more codes being thrown and the car is quiet again now. If you do go the patch route, make sure its done correctly because if not, then there will be some residual leakage which in turn may continue to trigger codes.

Boomer01

I think my car has a similar problem. The check engine light came on a few weeks ago and the dealer said it was the cats starting to go bad. He said to take it to a muffler shop instead of paying the insane dealer/oem prices.

Kira X

iTrader: (24)

Can you replace the factory cat with a Magnaflow high flow cat?

curiousB

Maybe but why? Fix the leak, cats don't fail often, bigger problem is the poorly designed Y pipe that leaks where clamps for heat shield exist.

Kira X

iTrader: (24)

I was going to go with a custom X pipe anyway so I thought I'd check.

peafarmer

I just replaced both the Y pipe and the two upstream cats with the ebay ones from Canada. They looked like quality components. I still have the check VSC light, so I took the car to autozone and they read no codes. Then, I took the car to a local shop, and they read no codes, and cleared all the codes. All was good for a couple minutes, but as I was driving away, the check VSC came on again. So, are there codes that some readers just can not see? I don't know where to start to solve this problem with no codes.

Also, I am getting some noise at around 60mph. As I say, the parts were quality, very heavy stainless, so I don't think the new cats and Y pipe are the problem. The shop said that the manifold gaskets were good. So, do I need a new muffler as well? How long do the mufflers typically last?

Thanks,
Andy