Originally Posted by Soo

Hello Everyone,

I have a 1985 CA 300TD with the oxidation catalyst recall upgrade. The EGR pipe broke a few months ago. After some research I decided to plug the oxidation catalyst's opening for the EGR pipe. The EGR valve appears to be in the closed position and responds to vacuum test properly, so I just plugged the vacuum line and left it in place.

Now there are 2 different kinds of noise. The first one is a high-pitch whistle-like sound that happens only during acceleration above certain RPM, and it happens whether or not the car is moving.

The 2nd sound did not start right after I plugged the catalyst, but weeks later. It could be related but I can't be sure. It is a low-pitch rattling sound that happens only when the car is moving. It feels like something is choking.

Further research has led me to this bypass pipe idea, which I hope can solve these problems. I am therefore checking with you experienced folks for some words of wisdom.

QUESTIONS:
- Is there anything I should know before I proceed with the bypass pipe?
- Where can I get the bypass pipe?

Thank you in advance.