I have a 2008 IS 250 AWD with 158,000 miles. I have a CEL and check VSC warning light. I figured out it was code P0420. I cleared it and it took a while come back on. After the second time clearing it, it came back on in about a week. Cleared it one more time and then it came back on after only a day or 2. But, after a couple days of it turned off by itself . After a couple days of no codes it came back on again and been on for a few days now.

I took it to the dealer and this is what they said, "CHECK VSC WARNING LIGHT IS ON, PLEASE ADVISE ~|~ ~|~154403 HAD DTC P0420/430 C1241 100 UPON INSPECTION FOUND EXHAUST MANIFOLDS AND Y PIPE NEEDING REPLACEMENT, EVERYTHING IS WELDED TOGETHER

Looking for suggestions on a fix that would be cheaper than dealer price. Thanks. (The dealer said like $700)

 

Seems to me like you need to replace the mid section of your exhaust system. That would definitely cause a disparity between the up- and downstream cats on your car. It could be a good reason to do an upgrade, or find a really good local exhaust shop that has a skilled labourer and go stainless if you can.

Dunno where you are, but if you're around Hamilton, ON go to Zorro in Stoney Creek. That guy does great work; 5 years on, and my front Y pipe is still solid!

 

Okay good to know, thank you

 

Do what I’m doing on my 2009 is250 awd and buy a invidia mid pipe and have an exhaust shop custom fit the driver side .

 

If I did need new headers, wouldn't that be more of a mechanics job rather than an exhaust shop?

 

I would bring it to a good custom exhaust shop. They ought to be able to cut out the corroded sections of pipe, then fabricate and weld in new. A P0420 or P0430 due to an exhaust leak is a VERY common problem with these vehicles, especially in areas where snow melting chemicals are used on the roads.

 

From the inspection report. Has someone already did a custom exhaust to the manifolds? For them to say it's welded together to the Y pipe. Also they might be saying of rust build up on the flanges. Which makes it look like it's a one piece.

 

I got the car about 4 months ago so I'm not sure. I can get the car up in the air and take a look in a bit.

 

Okay that's good to hear. So you think lexus quoting to entirely replace the exhaust manifolds and y-pipe is a bit overkill, because that's what I was thinking if you're able to cut out and replace the rusted areas.