> Just picked up a 1978 Spitfire that the previous owner had put headers
> on. That moved the catalytic converter farther down the pipe just under
> the transmission cover (it's a California car). The factory solution
> was to put the Cat right under the exhaust manifold.
>
> I had to have the thing smog checked. Since the new laws in this
> (f'ing) state require a dynamo test the car was running in place at
> around 35mph for some time. The catalytic converter got so hot it
> ignited the carpet that's over the transmission cover.
Rick, in addition to some heat shielding, I would be looking at the fuel
mixture and ignition. I know they can cause converters to overheat, don't
recall offhand if high HC or high CO is more likely to be the problem. Your
PO undoubtedly had to richen up the mixture to account for the reduced
backpressure, maybe he richened it too much for the cat. That would improve
performance, but could cause just the problem you're seeing.
Of course, you _could_ convert back to the stock exhaust system.
Technically, that's a requirement to pass the smog check, but perhaps your
shop doesn't know or care.
Randall
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