Running lean after CAI and muffler delete

Originally Posted by KeithF

I just had no idea that something as small as a muffler delete would affect it that much. I didn’t think it would count as an actual exhaust mod. I figured I would be safe as long as I didn’t go full cat back or mess with my cats. I think I’ll take it into my mechanic and have him check for vacuum leaks just Incase, but I doubt that’s the issue since this started happening right after install, unless I myself ruined some vacuum line somewhere.