Hey guys I have been running a k&n air filter in my stock Airbox on my 03 expy. I took the air filter out today for inspection and noticed a lot of dust particles downstream from the filter were there shouldn't be. Are k$n filters bad for your engine and should I clean the mas, iac and throttle body just for precaution. i did the GOTS mod but I'm sure that has nothing to do with it since the dust is after the filter

 

Well, I'd say a filter that has higher flow must have a coarser filtering grade, and would probably let through more of the finest particles. Besides, oiled filters tend to mess up the MAF-sensor over time so for me it's just not worth it... It's a debated thing, but I highly doubt you gain any sort of power or fuel economy from running a K&N filter, and you can find many tests where they dyno cars with various "performance" filters and cold air intakes, and usually finds that the stock air intake with stock filter performs best, though the difference is negligible in most cases..

 

+1 on a good paper filter. You also might not be getting a complete seal on the airbox if the band clamp is not on properly. K&N is pretty much a waste of money on these trucks TBTH and DEFINITELY don't fall for one of the aftermarket intakes since your modded stocker is better than any of them.

 

thanks guys I scraped the k&n and went back to a wix brand filter. Going on a 700mi trip this weekend so I am anxious to see if I have gained any mpg' with the GOTS mod and also a cleaned maf and throttle body