u/Mushy5555

I have a 2014 Subaru Forester (non-turbo) with about 206,000 miles. It recently started chugging and struggling to get up to speed on the interstate, so I decided to replace the spark plugs (they had never been changed).

After replacing all four plugs, the car now drives perfectly fine while moving. However, when I come to a stop (red light, stop sign, etc.), the RPMs drop really low (around 200 RPM) and the engine stalls.

I tried doing an idle relearn, but the car won’t stay running long enough to complete it—it dies within about 5 minutes.

Any ideas on what could be causing this or what I should check next?