I have an aftermarket K&N air intake system in my truck with a permanent conical air filter that requires cleaning as needed (estimated every 50k miles). I haven't noticed any drop offs in power or fuel efficiency, so I've never bothered opening up the box that it sits in to take it out and clean it. About a week ago, the check engine light turned on, and the Traction Control System and Stabilitrak started turning off for short 5 or 6 second bursts. When they turned off, the truck jumps when changing gears, but it doesn't happen all the time (typically happens 2 or 3 times on my drive home, a 40 minute drive). I brought it in to Autozone to get the check engine code and it came back as P0171. I decided to try cleaning the air filter. When I opened up the box that contains the filter, the filter's clamp ring had come loose and the filter was just bouncing around loose in the box. Thinking back, there was a clicking sound that started up over twelve months ago that I couldn't ever reproduce. I'm thinking that it may have been the filter bouncing around. If I've been driving around without an air filter for over a year, I'm concerned about potential dirt that's gotten into the engine/sensors that may not be working properly from getting dust on them. Is there anything I should do to clear out any dust that's gotten in there, or should I just put the clean air filter back on and let it be?
I personally do not like the aftermarket oil bath type of air filters with vehicles that have a mass air flow sensor. The oil that comes through the filter can contaminate the mass air sensor which would require regular cleaning with a special cleaner. The filter then requires a special cleaning and oiling process that, if not done exactly, will send extra oil into the mass air sensor again.
I would recommend having the intake system and mass air flow sensor cleaned. Afterwards, clean or replace the air filter making sure to clean and oil it properly. Then clear the codes and road test to see if problems continue. The entire problem may be due to a loose air filter. I’d recommend having your vehicle checked by a certified technician who can assess the condition of the components I’ve mentioned firsthand and diagnose the trouble codes to ensure your vehicle gets fixed properly.
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