Philhawtin

I have a 2000 A6 4.2

1 cat has blown the honeycomb out, therefor not allowing me to pass.

I am very broke at the moment and cannot afford a new cat+ sensors...

I would appreciate this help immensely

twentysevenlitres

You'll never pass emissions without a functioning CAT.

Find a 2nd hand one and a mate with decent welding skills...

GTA_Driver

How does your state test for emissions? Do they read engine codes and readiness codes? Do they put a sniffer to the tail pipe? Or do they physically bang on the cat to see if it's hollow?

You can install an oxygen sensor spacer, which will get rid of your check engine light and the cat code. Cheapest fix for your situation.

Philhawtin

Simple plug-in to obd. no sniffer no banging on cats

I have tried the spacer, tried 2 in fact... one with a mini honeycomb inside and one without... neither worked.

Philhawtin

Has anyone heard of soldering inline by the harness a diode to regulate return current to the ecm?

GTA_Driver

If an oxygen sensor spacer doesn't fix the catalytic converter below efficiency code, it's time to replace the oxygen sensor itself.

massboykie

I'm assuming Zener Diode?

This might work but it sounds like a stretch... Too many variables etc.

Then you may also fry your ECU and be in a lot $$$ trouble.

My 2c

Cheers
Massboykie