WhyteLexGS

So my 03 GS300 has been throwing this code for about a year now, I attempted to fix it 4 different times after doing some research on here, started with new O2 sensors then a new gas cap, went through 2 new cat's and the code is still coming on. Anyone have any other suggestions of what to check on? mechanic is a friend of a friend and said that the O2 readings look fine and the Cat's doing what it should be, running out of options and ready to sell it due to it not being able to pass inspection cause of emissions and the VSC being shut off when the CEL is on. So not ready to get rid of my unicorn with 89000 miles.

Long shot but can anyone in the NJ/Philly area suggest a mechanic in the area that is good and might be able to help?

Mr Jokster

iTrader: (8)

Have you searched for exhaust leaks?

kevin3344

Yep, after chasing this code off and on for a year the dealer diagnosed it as my Y-pipe. I have a '99 GS 400.

WhyteLexGS

yea I checked it for leaks, was the Y-pipe leaking?

kevin3344

Yeah, the dealer replaced it to the tune of $900 or so. Expensive! But my Indy was busy for a couple weeks out IIRC. A Lexus shop or the dealer can pinpoint it for you. Of course if you have an Indy it will be A LOT cheaper!! My Indy is about 55% of the cost of the dealer and they do a great job.

At any rate, my CEL would go out for a month or two, then come back. The car drove fine otherwise. Eventually I had it replaced and it hasn't come back.

WhyteLexGS

Hmm sounds like my issue when it started, since ****ing with it now the light comes on every other day once reset. Dealer said its leaking at the Y pipe however I can't find it, took it to a shop to put up on a lift they couldn't find it either. Dealer wants $2200 to replace it, going to see if I can get away with just putting a 02 sensor spacer on there.

kevin3344

I looked back at my records and my y-pipe was $1,115 at the dealer (motor mounts were $900). It could be because I have a 1999 GS400 and not a 300? Not sure what is involved in changing the y-pipe.

At any rate, if I were you I would have it fixed. Just helped my brother-in-law purchase a one-owner 1998 Lexus GS300 with 282,000 miles. He loves it. With 89,000 miles you have a car that will last and last.

I just purchased a 2002 SC430 from Florida with 104,000 miles the other day. It's on a truck to North Carolina now as I write this and I will mainly use it as a weekend vehicle. I know Lexus vehicles will run forever with proper maintenance; I'm not worried about the mileage in the least (especially since my GS400 has 225,000 miles). The first thing I'm going to do is have it checked out at the Lexus dealer and whatever they tell me it needs, I will have done.

AmanO

Am I missing something? What is the Y pipe?

I thought the Y pipe splits the single pipe from the manifold to the 2 for the resonators/muffles/tails.

Right after the cat? I got mine replaced for less than 300.

Were you guys able to have them unbolt and bolt new ones on? Either way, how is it so much?

Mcon

iTrader: (1)

My friend Aman0,

This the Y pipe how look in our cars.
OEM Y Pipe with the small cat at the end

Mcon

iTrader: (1)

WhyteLexGs,

Do you check if the Intake Air Resonator have a leak? Mine intake was detached just enough in the box, center area where they two plastic join parts go together and created the code. This air leak causes that when the extra air enters to the engine, the computer detects that needs more gasoline to make the mixture better on the engine. But in turn when the computer tells the system that need more gas, the two blends ( air and gasoline ) are richer and past for the entire system, cause to damage the catalytic in the end. Check that please. Also, the air hose after the intake manifold, some time are broke or loose. Good luck with that