My future brother in-law just recently placed a brand new cone K&N on his 03 F150 for his first mod ever. He has 50k miles on his truck and he told me that it ran fine for about a week or so, but then it started to sputter and bog down a bit, moreso at lower RPMs and that he also got the CEL. He got tired of it jumping around on him, so he threw the stocker filter backon and he said no more problems. He wasn't sure what was going on and he said the dealer wanted $100 just to hook it up to the diagnostics. I couldn't provide him with any useful insight, but I told him I'd check on here to see if anyone had experienced the same issues or had any thoughts on what was going on or what he could do. Thanks in advance for the help. :rockon: