Just installed a header on my milltek exhaust and the sensor on the header before the catalytic converter is currently pressed against the heat shield with everything in tightened down. I bought the headers with the exhaust and the previous owner told me the whole system was for an r53 and the headers were a "generic" brand. The headers were connected to a test pipe so im assuming theyre megan headers. Any remedies to allow more breathing room? (i also took a hammer and pounded on the heat shield but that didn't give it much more clearance.)

 

There is some play in the heat shield, but if the hammer did not create more clearance might need to weld another o2 bung in. An 90 degree o2 extender might correct the interference but I would think the car would not run correctly as the ECU would not be getting a good read on the fuel mixture.