Anyone have this issue. My 2015 Volvo S60 T5 started idling hard on my way home from work the other day. Found those two error codes, looked up some causes and found that Volvo recommends changing spark plugs and coils every 70,000 miles. My car has 139,000 miles. So, I order new plugs with coils from a Volvo parts dealer, check to make sure all is good, and install them. I was pleasantly surprised how easy it was, especially coming from a 2003 Jeep Wrangler, that thing was awesome to work on. All installed correctly, and I figure I am done, problem fixed, NOPE. Error codes P0304 and P0305 are still there and car is still idling hard and showing a warning to shift up. Any help would be greatly appreciated! Thx all, Steve

 

Did you clear the codes after the install and then they reappeared, or are they leftover from beforehand?