WS7 Exhaust Gas Analysis

With the gas analyser sensing normal air, the gas readings are
C0 0.001%
HC 15
Co2 0.01%
02 21.23%
These readings show the air around us, without much contamination.

With the engine idling while cold you get these readings:
CO 1.038
HC 156
Co2 14.42
O2 0.82%
As the catalytic converter has not warmed up yet, the car is emitting a lot of CO.

3.The engine has warmed up now and the readings are:

CO .727

HC 181

CO2 13.49

O2 1.9

This shows that the catalytic converter has started to work to reduce emissions.

4. The engine is warmed up and running at 2500 RPM the readings are:

CO 5.5

HC 419

CO2 11.14

O2 0.29

As the engine is at a faster speed, it obviously must produce more emissions.

5. At idle with a richened fuel/air mix the readings are:

CO .707

HC 100

CO2 14.08

O2 0.45

I don’t think I made the mixture rich enough as the readings were the same as the engine warmed up.

6. At idle with a lean mixture the readings are:

CO 0.129

HC 66

CO2 13.92

O2 2.54

As there is an air leak, the O2 reading is high.

7. Under acceleration the readings are:

CO .676

HC 198

CO2 8.03

O2 .192

As the mixture gets richer with acceleration, the CO reading will get higher.

8. Disconnected spark plug wire grounded by a jumper wire, and the readings are:

CO 2.3

HC 3978

CO2 9.06

O2 8.27

As one cylinder is not having its fuel/air mix burnt all the readings will skyrocket.

Disconnected one injector, the readings are:

CO 737

HC 270

CO2 8.82

O2 8.6

Showing that the injector is open, as there is more fuel being unburnt.

The readings on a car without a catalytic converter would show that there is an excessive amount of CO,HC and CO2 that is being put into the atmosphere. As the ‘cc’s job is to reduce these emissions.

A car with a cc would have far less emissions once the cc has warmed up to operating temperature. The cc then converts CO and HC into CO2 and H2o.

O2 sensors can have many wires.

• One is for the positive heater.
• One is for the negative heater
• One is the output to the ECU
• One is for the temperature