..surely due to missing cat. '86 951, the NOx reading was like 2900 or about 2.5 to 3x the max acceptable. I went to a private facility and can drive the car for another 2 months before re-inspection is required.

Does anyone know my options? I was thinking of using the SFR hi-flow cat, but see that repairs must be made at a certified facility. Can I make the repair independendly and re-test? I'd like to install a high-flow cat, if I can get the whole thing done for <$300 or so.

Also, what might be needed to get a waiver?