Contents Wiring diagrams Section: Exhaust All sections

Engine Exhaust System: Overview Chevrolet Spark M300

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3 The exhaust system has very low back pressure under normal conditions. If the exhaust system is restricted, a significant increase in the exhaust pressure is noticed on the J-35314-A exhaust back pressure gauge. Removing the heated oxygen sensor may set a DTC. When finishing this diagnostic table all codes must be cleared.
  2. 4 This step will isolate the catalytic converter from the remainder of the exhaust system.
StepActionValue(s)YesNo
Special Tools J-35314-A Exhaust Back Pressure Gauge
1Did you verify the customers complaint?Go to Step 2
2Did you review the exhaust symptoms diagnostic information and perform the necessary inspections?Go to Step 3Go to Symptoms - Engine Exhaust .
3Remove the heated oxygen sensor 1. Refer to Heated Oxygen Sensor Replacement - Sensor 1 . Install the EN-35314-A exhaust back pressure gauge in place of the heated oxygen sensor 1. Start the engine. Increase and monitor the engine speed at 2, 000 RPM. Observe the exhaust system back pressure reading on the gauge. Check the value.Go to Step 4Go to Step 4
4Turn the engine off and place the ignition in the lock position. Remove the EN-35314-A exhaust back pressure gauge. Install the heated oxygen sensor 1. Refer to Heated Oxygen Sensor Replacement - Sensor 1 . Remove the heated oxygen sensor 2. Refer to Heated Oxygen Sensor Replacement - Sensor 2 . Install the EN-35314-A exhaust back pressure gauge in place of the heated oxygen sensor 2. Start the engine. Increase and monitor the engine speed at 2, 000 RPM. Observe the exhaust system back pressure reading on the gauge. Compare the reading with the above value. The values are same?Go to Step 5Go to Step 6
5Inspect the exhaust system for the following conditions: Damage in the exhaust pipe Debris in the exhaust pipe Muffler or resonator internal failure Two-layer exhaust pipe separation Did you find and correct the condition?Go to Step 7
6Replace the exhaust manifold. Refer to Exhaust Manifold Replacement . Did you find and correct the condition?Go to Step 7
7Remove the EN-35314-A exhaust back pressure gauge. Install the heated oxygen sensor 2. Refer to Heated Oxygen Sensor Replacement - Sensor 2 . Clear any DTCs. Road test the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 2

Restricted Exhaust