Po432 - 97 E420
 

- Main Catalyst below threashold (bank 2).

Which side cat is it talking about?

Left side (drivers)!

Thanks - Now for the 02 sensors
 

OK the car had a clogged cat about a year ago and the guy who had it fitted a universal fit Cat that gave out recently and threw this code. It seems like the cat is falling apart now because its rattling all over the place. The car runs well and has not thrown any other codes so I am thinking that the 02 sensors are bad also and as a result distroyed the cat. The car has 92000 miles on it.

How many O2 sensors are on that side and do I need to replace all of them or just the two that sit in front and behind the cat.

Hmmmm.....I was told by a well-respected MB mechanic that aftermarket cats won't work on OBD-II cars.

Aftermarket cats have always been junk. Its just with OBDII, the computer tests them and tells you they are junk.

When all a cat needed to do was take the exhaust down the line, aftermarket did the job. Take a look at any of them, compare to an OEM, weigh them. It doesn't take a research scientist to see the difference. Like many things, one gets what one pays for.

California or Federal
 

Ok so the next question. I just tried to buy a DEC cat and they asked me if my car comforms to Federal or California standards. He said that 99% of cars conform to only Federal however if mine does not, I will burn up the cat. They only sell Federal complient cats.

How do I find out?

Bit the bullet
 

Well I called the dealer and asked about the cost of a replacement cat .. The local dealer (RBM) wanted almost 1600 dollars for a replacement saying that the cat itself is 1350 dollars. My old dealer (park place in Dallas) would sell it for 800 and something. I don't care how much better a Mercedes Cat is I am not paying 1500 for a catalytic converter. I took it to the muffler shop recomended by a trusted tech and they looked at the cats. It appears that the factory front cat fell apart and blew into the back cat and hence rattled all over the place. He replaced both cats with high output cats (small and designed for cars up to 6 litres).

Total cost for replacing 2 cats is $450. If it lasts three years it would take me 9 years to break even.