Recently did a home service on my r53 '06 MCS - oil and filter change, spark plugs (DENSO 5304 iridium), air filter (oem from minimania w/ pinkish seal), cabin filter. A few days later my service engine soon light came on while on the freeway. I've tried restarting the car several times and it still stays on.

Coincidentally I hear a hiss sound at a certain somewhat low rpm and certain throttle level, sounds similar to what people describe with cold air intakes, but have a stock intake here (don't recall hearing this before, but can't be sure). Not sure if I might have messed up installing the air filter, or maybe knocked something loose. Any ideas?

Anyone in the bay area (san jose) have a OBDII code reader I could swing by and use?

Thanks for the help.

 

Checker, Kragen, Advance, Autozone, etc. have readers you can borrow to pull codes. Find one close by and bring the result(s) back here and I'm sure you'll get lots of help and advice.