They usually are.I guess that was a poorly designed CAI.
Have removed many “high end” CAI because they were causing metering faults.
They usually are.I guess that was a poorly designed CAI.
Look under the top part of the airbox I bet there's one there. Many cars have these and it's probably a form of idiot proofing.I don't have one of those on my 2018 Hyundai Kona AWD 1.6T. It would be long gone if I did though. Nore do I remember one on my wife's 2013 Elantra GT. Is your car a California car?
Agreed, changes in things like Abs P before and after the throttle body, and the MAF readings with just a filter change may basically be in the noise level and hard to get any confident change data at idle. The MAF data at WOT vs RPM would be more accurate as long as there wasn't some turblance factor. If the intake designer did it right, the MAF sensor won't be in a turbulant area of the stock intake tract regardless if a filter is installed or not.The amount of air the engine ingests at idle under the same conditions shouldn't really change going from one filter to another. If the secondary filter was indeed restrictive, that restriction would become increasingly evident as load and engine speed increased.
What caused me to raise an eyebrow was the air mass idle reading, which shouldn't have changed with the TB being the biggest restriction in the system which is why I tossed that out there. This is where vacuum measured in front of the MAF using a restriction gauge or sensitive vacuum gauge would be helpful in determining if restriction did in fact change or if we are just seeing an artifact of the airstream changing due to the elimination of the secondary filter.
Is this "charcoal filter" really upstream of the main filter? If so, is the air actually going through it before the main air filter? Or is this just mounted in top of the air box and it just acts as a charcoal absorber (that's my bet). I'd think it would be way more dirty than it is if it was actually acting as an air filter, and not just a gas fume absorber.Quick question, Ive noticed on both of the Hyundais 2009 Elantra and 2013 Sonata, I see a "DO NOT REMOVE" printed on this air box intake secondary filter upstream of the main filter on the lid.
It's downstream of the main filter.Is this "charcoal filter" really upstream of the main filter?