When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
That a nice pile of BS. I have had my Y pipe on for a year now and just put on an intake two months ago and have had no problems what so ever, and no CEL.
Your CEL may trip if an O2 sensor gets dirty or damaged during the Y-pipe installation. If they're dirty, just wipe them down with isopropyl alcohol or fuel injector cleaner.