akitamike

Prior o

Bill Ball

Don't these cats need air as well? I have the same cats and have my air lines hooked up. Could be why your HC is high.

Bill Ball

OK, I see where RT cats don't require the extra air for oxidation. Anyway, I would make sure the diverter valve is set so the air from the pump goes to the air filter housing or take the belt off the pump.

PorKen

Running the pump closed will kill it for sure.

There is a place you can unbolt the line to the cat under the car, I would imagine the muffler guys clipped the line after this connection, just disconnect it here.

You could remove the diverter valve under the air filter box, and run the hose from the air pump directly into the airbox. (The diverter valve has three connections, air pump, cat, and the airbox.) This would be the quietest option, I reckon.

A bit more involved, but you could open up the air pump, and remove the vanes inside. This would free up a few crank HP.

cfc928gt

I have my pump line plugged where the line from the cat attached and the air pump belt is still on, no problems.

928drvr86.5

Why not just remove the pump Fred? It's easy to get it back to stock, at least for my 86.5. Dead heading that pump Can't be good I'm thinking. Do you have to re-install your stock cats for Emissions testing in Denver?

cfc928gt

Ben, how are ya! Just got my rebuilt LH back from Rich this past week, thanks again for the certificate. I had to put my cats back on to pass emissions this summer, I tried first to pass without them but it just barely failed. As far as the pump goes, I asked about running it with the end plugged and Jim B said it wouldn't hurt it so that's what I've been doing for the past couple years with no problems. I've thought about removing it but haven't done it yet. From what I understand it doesn't take much power to spin it, all the guesses I've read about estimate it to be less than one horsepower.