Hello, We just bought a 06 Nissan pathfinder and noticed the SUV running rough in idle, but the check engine light wasn't coming on, so we decided to scan it, and of course, we had a code. We fixed the code, but how do we fix the check engine light? All the other lights work except the service...

Looking at a 2.5 turbo diesel with minimum 250k km or 155k miles what problems should i be looking out for?