YODAONE

Before extracting cylinder heads with exhaust manifolds, removed catalytic converters.

The top and bottom flanges of converters are in very good condition, but the area where the compression gaskets nestle in front flanges of y-pipe are ragged.

The y-pipe appears in good condition otherwise, so am interested in replacing the flange...and while at it, removing the sharp transition after the flange.

Toyota/Lexus decided to weld a straight section of 60mm pipe to the cat outlet flange, angle cut it, weld a 50mm pipe pipe that has its last couple of inches expanded to 60mm and match angle cut. Incredible amount of turbulence. The post-catalytic 02 sensor probe presents a considerable obstruction to exhaust flow...a wider pipe at this area would offer improvement.(post car O2 sensors report if converters not working)

Anyone recommend source for quality flange with correct material and dimensions (including compression gasket undercut?

Alternatively, like new1998-2000 LS400 front y-pipe undercut depth.

Had considered using the catalytic converter flange as a template, however am unsure whether gasket undercut depth is same....

Thanks




Catalytic converter flange depicting undercut where gasket nestles.