I have a 2006 Honda Ridgeline with 300k miles. I’m having a code 2279 with a rough idle which will surge at times when in park. Previously i had the 2279 with misfire codes on all cylinders and rich codes for both banks. It was hesitating from a start as well. Did a valve adjustment and replaced intake and valve cover gaskets and misfire and rich codes are gone but 2279 is back along with 0420 bank 1 catalytic converter below threshold. I have checked everything Multiple times looking for a vacuum leak with propane, brake cleaner and water and can find no obvious vacuum leak. It runs great at highway speeds and has no stumble in acceleration. Another issue is with the power steering which has a whine. I’ve replaced the pump o-rings which helped some. I mention this because I have seen some things which indicate this could have some impact on the idle and I’m wondering if there’s a vacuum connection associated with the steering. Any thoughts or direction would be greatly appreciated. I’m wondering if the evap purge valve could cause this issue, and if there are any other related things I should be looking at. Many thanks in advance for any advice.