996 Vacuum

[engdavis]

I've been reading this forum for about two weeks and the information has been great. I just bought my first Porsche (1999 996 C2 Cab) and really enjoy it. Mostly commuter driving but the commute seems shorter now.

I installed the K&N air filter element right after I bought the car and within a day had the infamous P1124 and P1126 codes with the CEL. After reading how many others have had this with K&N and other after market air filters, I took out the K&N and replaced it with a new OEM paper filter. Continued to throw CELs every couple days, and attributed that to residue from the K&N filter oil (came pre oiled in the bos) but after a can of CRC MAF cleaner I hope those are a thing of the past. It's been three days since the last cleaning of the MAF, the entire inside of the air box and the air intake bellows and so far no CEL.

If the CEL returns my next steps will be a thorough inspection of the vacuum lines and there lies my question. Is there somewhere I can find a schematic of the entire vacuum hoses system? Looking in the engine bay it's hard to determine exactly where all the vacuum lines are and I don't want to remove or disassemble things that don't increase accessibliity to vacuum lines or connections. I would also like to know if there is a step by step instruction posted for the oil separater bellows replacement. I've heard that can also cause the CEL but I don't know where it is located. The car has 56000 miles and runs great. Even with the CEL on there is no noticable decrease in smoothness, fuel economy or throttle response.

I've also noticed some oily film in some areas of the engine bay but it looks like just old dust and dirt accumulation, nothing major and no "wet" areas. No obvious oil or coolant leaks anywhere.

This is a great forum, thanks for all the good info.

Regards,

Mike D.