I have the exactly same problem on my 2003 LS430. There was a leak on the passenger side behide the O2 sensor just inside the heat shield. I took it to local repair shop. They cut out the leaking section and welded a new pipe for the area. It cost only $80. But the heat shield was taking off. Anyway, it's a quick fix for the leaking and noise.
I had the same problem and got it resolved by having my muffler shop welding two new pieces of straight pipe for $150...I have driven over 500 miles and the codes have not reappeared!!
Fault Codes P0430 And P0420 On Ls430
in 01 - 06 Lexus LS430
Posted
I had the same problem and got it resolved by having my muffler shop welding two new pieces of straight pipe for $150...I have driven over 500 miles and the codes have not reappeared!!