Alberto, I bet your MAF would've failed at the same day, same time anyway. Imo efi is a smog device, and the maf is the weakest link. I do not believe the K&N caused it to fail. There is no way that you or I can prove either way, but I had to throw in my 2cents.

Hey, I've been dying to take one these MAF sensors apart. If you would be willing to ship it to me I'd pay you the $5 or whatever shipping. I'll also post pix of the inside if anyone cares to see.