greasybenz

i have a 2002 C32 AMG. The check engine light came on and the OBDII scanner read these codes:

P0150 Map/barometer Circuit Malfuntion
P0432 Main cat below threshold bank 2
P0422 Main cat below threshold bank 1

The first time the light came on i took it to my mechanic and he had cleared it saying if the light comes back on to take it back. When it came back on the same codes came up but then i got a ticking noise along with it. Sounds as if its the supercharger making the ticking noise.

Any idea whats wrong with my car?

boohooramblers

Find out where the ticking is coming from - if it's the driver's side of the engine bay, then it's most likely the infamous purge valve ticking.

ohlord

and a bad o2 sensor.how many miles on the car?p0150 is an sae non manf specific code for the o2 sensor drivers side pre cat open circuit
if under 80 k miles dealer will test the cats and replace them if faulty or failed.How is it running?besides the ticking sound.
with the SC you should not drive it much until you until you get it checked out,no need to do any more damage.
Doubt it is the purge valve ticking they rarely get loud enough to hear inside the car.If in the rare case it is,clean it per my diy on the diy section of benzworld.org w210 section
ohlord

greasybenz

If the purge valve is the part with vacuum hoses connected to it on the front driver side of the engine bay then thats whats making the ticking sound. You cant hear it from inside the car only with the hood up or muffled with the hood down.

The car has high miles (105K) But its running fine even with the cats the way they are. No hit on performance.

boohooramblers

Yep - your purge valve is what is making the 'ticking' noise. In some people's cars, the noise is mild. In many others, it is a real pest that can be heard clearly inside the cabin. It doesn't seem to deleterious to normal functioning - it's just a nuisance.

There are many links on the C32 and W203 forums about the problem. Here's one link that describes the problem and a discussion on the remedy (replacing a metal fastener).

greasybenz

Cleaned out the purge valve and the ticking is gone! Now if i can only figure out whats going on with the cats, the check engine light came back on today Since im out of the warranty would it just be easier if i replace the cats?

MB_Forever

Check the O2 sensor, might be time to replace them.