Coming in the mail is a Titan catless downpipe and a JB4 piggyback with the Bluetooth and EWG cables.
I plan on installing these together. What can I do to make sure I won’t get a CEL code upon install?
You can try with an o2 extender, but most likely you'll still get a CEL. JB4 cant change the ECU parameters so until you can tune it, you'll have to live with a CEL
You could swap for a catted downpipe that is guaranteed not to cause a CEL. That's as close to foolproof as I can think of. Active Autowerke is the only one I can think of that is guaranteed, but I think a couple people still got a CEL even with this one. Only drawback is that the catted version is $500+ more than the Titan one.