I doubt this will be your problem since you said you've already got almost 800 miles on it ... but.. I have the same year and model. I took my back to the dealer 3 or 4 times for the same problem and codes. Pull the plugs and see how much sealer (looks like white teflon tape but it's sprayed on). My electrodes were fine, but the threads were covered top to bottom on the plugs preventing them from properly grounding. They installed some new OEM plugs and wire brushed back the sealant baring 1/2 of threads. Instantly fixed..never another problem. I doubt that's your deal...but it's easy to check. The plug threads should be only sealed part way down..not all the way. It's a known problem at least for 2018 turbo X-3s. Good luck. Keep us posted.Hi HP - You know, I have not tried it in reverse! I will try this this weekend around the block. So far this on forward movement only, and will not show up at idle. Only after moving forward for short bit.