UPDATE (11/25/24): I just fitted it to the car as seen in the photo, its a very tight fit on the MAF and the air box lid, I took both of those off the car to be able to twist it on. The inside diameter is 70mm, I'm uploading a version with a 71mm ID but it won't be test fitted. 

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Filter to MAF flexible intake boot replica for the 2001-2006 Kia Optima with the 2.4 engine. Also should fit the 1998-2005 Hyundai Sonata as they share the same part number. 

The original boot part number: 28138-38200

This part has been discontinued and is difficult to source new, most used boots are likely to already be ripped. I modeled it to be as identical as possible to the original rubber part, so its design doesn't lend itself to 3D printing and requires a lot of support.

Print Settings (I used Bambu Studio):

• Material: TPU (I used Overture High Speed TPU)
• Infill: 100%
• Supports: Tree supports (auto) from build plate only, optionally increase the support to object spacing by 0.5mm
• “Draft” quality layer height recommended for speed of printing,

I printed this on a Bambu A1 Mini with the generic PLA settings in Bambu Studio using the Overture High Speed TPU. It's Probably 25-50% stiffer than the 20 year old rubber boot off the car but should function the same and be compliant enough. Reducing infill below 100% not recommended. 

I found the support material very easy to remove even with all the tight clearance overhangs, if it's too difficult you may need to adjust settings. Some overhang droop is expected. 

Make sure there isn't any loose material on the inside that can get sucked into the engine!!