All,
I'm hoping to help a good friend with an 03 Boxster S. The car has a KN intake kit. He recently cleaned and re-oiled the filter and now it is running rough below 2,000 rpm. He thought he may have gotten oil on the MAF sensor, so he bought cleaner and cleaned the sensor. No change in the rough running. I believe he know has a CEL. I have no equipment to read codes.
If anyone has any suggestions please let me know.
Thanks

 

This is usually the MAF, try cleaning again or possibly a new one!

 

Need to read the code(s).

 

You can get relativity inexpensive videos readers I thing a member on here has a new Bosch unit that works well from what I've seen.

Best to avoid reusable filters and stick to a paper medium.

 

if too much oil, clean the filter again, wash it , let it dry a day or so, and oil it a whole lot less. It needs hardly any oil, just a sheen. I use Pam veg oil.

 

If you don't have a generic OBD code reader, many of the parts chains will let you use theirs.

 

"Cleaned and re-oiled the filter" is the answer to your question.

Did your friend really need to clean and oil the filter? K&N recommends a 100,000 mile interval for their cone filters, 50,000 for airbox replacement (drop-in) filters. I have never actually met anyone with a Porsche who cleaned their K&N filter because it legitimately needed it.

He'll need a new MAF - getting them working properly after over-oiling is a crapshoot. I would also go with a new filter (probably one of the new oilless ones...), and I'd use a filter sock to filter out the bigger particles that make the filter LOOK like it needs cleaning.

Filter sock:

 

5chn3ll,
I'm not sure why he felt he needed to clean and re-oil the filter. Seemed like a dumb idea to me also. Unfortunately he did it before he talked to me.
Thanks all for the advise.

 

What others said, sounds like MAF. Should also suggest he swap it out for an OEM airbox.