Hey Dave:

Do you have pics of your headers and the failure spots? Also, what are the specifics on your engine, i.e. HP, naturally aspirated / SC, NOS, etc? In a perfect world with POLISHED METALLIC CERAMICS and a perfectly tuned (timing and fuel) engine that was NOT exposed to any engine break-in procedure or Dyno tuning, you will see slight dulling approx 8-12 inches from the head. Anything more severe or further out in the primaries is indicative of a lean condition. Conversely, dulling and coating failure from mid primary out to collector is indicative of a RICH condition. The after-burn in the headers over heats the ceramic coating which opens its pores are allows it to begin rusting. Or in more severe scenarios the polished ceramic will become sacrificial and begin to delaminate from the header substrate.

I've re-coated numerous TTI headers over the years as well as others in similar applications and unfortunately their failure is usually the result of excessive temps for the Polished Ceramic. Most people don't realize its true temperature limitations because its a go-to coating for many header manufactures and most lie about its abilities. That said, Polished Ceramics at their base are nearly all IDENTICAL in chemical formulation. That rating is 1000F to 1100F METAL TEMP. That can be extrapolated to approx 1100F to 1300F EGT. Companies claiming anything beyond this are clueless or lying. Its physics. The aluminum material in the coating that makes it shine oxidizes at 1000F to 1100F PERIOD.....

That said, the only solution to the normal 1-3 year life cycle of Polished Ceramic is to use a High Temp Ceramics which are rated at near 2000F. High Temp Ceramics are not offered in a polished finish but they are available in upwards of a dozen color options. In that we do a lot of higher HP cars or newer vehicles with superchargers, turbos, etc we do probably 95% High Temp Ceramics these days.