The waveform clutter of the oxygen sensor is caused by the cylinder with poor ignition. How does the poor ignition of the engine cause the clutter?

The burr and clutter on the waveform under the condition of poor ignition are caused by single combustion time or series of combustion events with incomplete or no combustion, which leads to the effective oxidation part being utilized in the cylinder, and the remaining excess oxygen goes to the exhaust pipe and passes through the oxygen sensor. When the sensor detects the change of oxygen composition in the exhaust gas, it will produce a low pressure or burr very quickly, and a series of these high-frequency burrs will form what is called "clutter".

Different types of poor ignition that produce burrs.

A) Poor ignition caused by the ignition system (for example, damaged spark plugs, high-voltage lines, distributor covers, distributor heads, ignition coils or primary ignition problems that only affect a single cylinder or a pair of cylinders). Usually the ignition oscilloscope can be used to determine these problems or eliminate these faults);

B) The poor ignition (various possible reasons) caused by the rich mixture sent to the cylinder is about 13: 1 for a given air-fuel ratio of dangerous mixture;

C) Poor ignition (various possible causes) caused by too thin air-fuel mixture sent to the cylinder is 17: 1 for a given dangerous air-fuel mixture;

D) Poor ignition caused by cylinder pressure, which is caused by mechanical problems, reduces the pressure of fuel-air mixture before ignition and cannot generate enough heat, which hinders combustion and increases the oxygen content in exhaust gas. (such as valve burning, piston ring fracture or wear, cam wear, valve sticking, etc.);

E) One cylinder or several cylinders have defects caused by vacuum leakage, which can be determined by adding propane to the suspected vacuum leakage area (intake impeller, intake manifold pad, vacuum tube, etc.). See when the waveform of oscilloscope becomes more signals and the peak disappears due to propane addition. When the mixture entering the cylinder due to vacuum leakage related to one cylinder or several cylinders exceeds 17: 1, poor ignition caused by vacuum leakage occurs.