🔍 Key Concepts

• diesel exhaust system components (manifold, piping, muffler) • relationship between flow restriction and back pressure • difference between combustion/injection issues and exhaust path issues

💭 Think About

• Ask yourself: Which option would most likely block or restrict the exhaust gases trying to leave the engine? • Which choices describe problems inside the exhaust path, and which describe problems with fuel injection or temperature? • Would eroded or worn-away parts in the exhaust make it harder or easier for gases to pass through?

✅ Before You Answer

• Identify which answers involve the exhaust gas path after the cylinders (manifold, muffler). • Decide which condition would physically narrow or obstruct that path, raising back pressure. • Separate issues that affect combustion pressure (inside the cylinder) from those that affect exhaust back pressure (after the exhaust valve).