Trap cat test pipe finished - 1985 300D (CA) W123/OM617

[Jeremy5848]

The machine shop finally finished building me a test pipe with which I can temporarily replace the trap catalyst on my 1985 300D-T (California version) for testing purposes only. The car has been torn apart for three weeks waiting for the test pipe to be finished; I'm looking forward to putting things back together this weekend and seeing the results.

To begin with, I'll admit that the "swap in a complete Federal exhaust system" proponents were right. The machine shop billed me for four hours of work -- making a jig based on the trap cat, machine work to clean up the cut-off ends of the junkyard trap cat, welding and grinding, etc. One could surely buy a complete Federal exhaust system including the turbo for less than that. Then one would be able to share in the joy of dealing with collapsed air-cleaner mounts as many forum members have bemoaned.

The pictures I have attached show my original trap cat and the finished test pipe side by side. The test pipe weighs 3.5 pounds (1.6 kg) compared to 14.5 pounds (6.6 kg) for the trap cat. The labeling on the side of the trap cat is shown in the second picture. Some folks were asking about that. The part number is 126 490 34 14.

When I took the car apart, I discovered that there was no gasket between the exhaust manifold and the trap cat (three-bolt junction). This is strange. The EPC doesn't show one either. Then again, it doesn't show one between the trap cat and the turbo, even though I found one when I took the car apart (four-bolt junction). Anyone know if there's suppose to be a gasket between the manifold and the trap? Does the Federal car have a gasket between the exhaust manifold and the turbo? The EPC doesn't show any gaskets except for the long manifold-to-head gasket.

I'll report on results once I have the car back together. By the way, machine shops in my neck of the woods now get $100/hour, almost as much as my dentist.

Jeremy