so my 2014 fiesta st has 60k miles with a muffler and res delete. I have been running stage 1 cobb ots for at least 15k. regular maintenance oil changes at 3k and all. yesterday morning I was running a little late and ran it cold. Not hard mind you i stayed out of boost but below 2k it registered negative 1 for corrections on all cylinders. Afterwards it has been running heavy negative corrections on all cylinders whenever I hit boost. I thought fuel might be an issue so I dumped it down to the stock tune. Still negative corrections. I pulled the plugs and they look fine. Reset the ecu and still having issues. Anyone have any ideas what might be going wrong? thank you for your help.