If you have to undertake maintenance tasks to your Norton Commander then it is always a good idea to have a Workshop Manual to use as a guide should you need to know methods to take out a particular part including Exhaust and fit it again properly.
Norton Commander Workshop Manuals will give distinct diagnostic info for your automobile so if something is broken it helps you determine what the problem is and how you can fix it. You will be able to evaluate if this can be achieved by yourself or that the job is too big you can still make a booking for your Commander in with a suitable garage.
Norton Commander manual