Hi. I have a 2003 C230 Kompressor with a pesky P0410 check engine light. My dealer charges $200 just to diagnose. I opened the hood and found the hose going to the valve was rotted and replaced it. It worked for three weeks (usually came on in three days), and suddenly the check engine light is on again. I saw someone replaced spark plugs and mine had never been replaced (16 years, 140,000 miles) so had that done and the guy there did a "smoke test" and said my crankcase breather hose was leaking. He quoted $580 to fix.
So TWO QUESTIONS -- would a leaky crankcase hose cause a P0410 error message (I have not seen this mentioned online), and what is a reasonable price to repair?
BTW, this crankcase hose was apparently recalled (TSB 2008020002) in 2008 but my dealer said no outstanding recalls for my car (but I don't see this was done).
Thanks!

 

moved to W203 forum...

 

This was a "campaign" not a recall, and my "vent hose" was indeed replaced in 2008 70,000 miles ago. Still want to know if a crankcase hose is related to the secondary air injection system fault, and how much it should cost to repair. Thanks!