JSK333

I'm probably getting a set of the Pacesetter LTs, and am trying to decide whether to keep the EGR/AIR or not. We don't need it for our emissions test here.

I know that EGR helps reduce emissions somewhat and won't affect WOT performance. However, I believe with the Pacesetters it's either both AIR and EGR, or neither.

My question is: will running (or not) an AIR pump with true duals and two cats make a difference? Won't the AIR pump only push air to one cat on a true dual setup? If so, is it necessary?

I've seen all the arguments about "needing" the AIR pump to keep the cats functional, but isn't it really a matter of getting them to work sooner by increasing hot airflow to them?

So, main question: does a true dual setup with two cats NEED an AIR pump to function properly?

TIA!

JSK333

Anyone know for sure?

Injuneer

The AIR pump does not supply any air directly to the cat.... that was ditched with the start of 4th Gen production. The 4th Gen setup flows AIR for about 2-3 minutes after startup, to the connections in each exhaust manifold (or header). Hence, it supplies the air to heat up both sides, whether you have one cat or two, Y-pipe of duals.

Yes, as far as I know, it only provides air to oxidize (burn) the rich startup mixture exhaust and provide heat to get the cats working faster. Some people have speculated that without the AIR, the cats will get soaked with fuel, heat up, and melt down from excessive heat when the engine warms up. I have never seen any actual data to confirm that, and there seems to be a lot of people running cats and no air, and no melted cats. I ran mine for quite a while after the stroker rebuild with dual high flow cats and no AIR. The cats survived.

JSK333

Thanks for the input, Fred!

So, does this mean that aftermarket headers with emissions hookups have AIR connections on both sides too?