[Tom Wells]

C5,

I have flanged headers and EFI. One way I can tell I've got a flange leak (sensor is only an inch or two away from the flanges) is when the car starts running pig rich. Then it's time to replace that collector gasket.

Another way to tell is to run at highway speed a few minutes, then back off the throttle suddenly - if there's a leak I'll get a big bang (backfire) out of the exhaust on the side where the leak is located. Replace the collector gasket.

I've tried lots of different flange gaskets and they each seem to develop leaks sooner or later. Some are better than others but so far I haven't found one that is immune.

The only header attachment I've had no problem with is the V-band clamp. It just works. The clamp won't work where the individual headpipes are located - only where the 3" collector can be attached this way.

You pays your money and you takes yer cherce!

Tom