BMW 325i smog check did not pass due to high HC

1994 BMW 325i smog check did not pass due to high HC. Smog technician said I may need to replace the catalytic converter, however this was a pretest and before I spend $400 should I spend some money to better diagnose the problem. The HC was 177 at 1977 rpm and 113 at 1872. Is there another test to make sure the diagnosis was correct and how much will is cost?

Answer:

Great question and in fact there is a test which tests the Catalytic Converter specifically. It's called the CAT Intrusive Test. A smog repair station will take an exhaust sample before and after the CAT. It's called "intrusive" because most often they need to drill a small hole before the CAT to get the pre-CAT sample. This test will show the CAT's efficiency. You may run into the only problem of a smog station not willing to simply conduct a CAT test without testing the entire emission system. Typically smog failure diagnosis runs about two labor hours. The average labor hour should cost $60 to $70 dollars.

posted by SmogTips Support