[Stan]

Originally Posted by Daox

I took exhaust pipe temperatures from just behind the cat. The exhaust manifold on the car comes out the front of the engine, then wraps around and goes toward the back. The cat is probably a good 5 feet from the head.

I have to wonder if the distance is the issue. Can you get thermal readings right off the head? If so, I bet you'd see the temp coming up within seconds. The reason being that there is a great deal of thermal mass in all that piping and cat to bring up to temp before the tail pipe gets hot where you measured it.

Thanks for sharing, though...good stuff!