The first test I had to do was start the car and let it idle cold and record the readings.It usaly takes about 30seconds for a acuarute reading to show.I got readings of:
CO:49% HC:340ppm CO2:12% O2:0.6%
The engine getting warmer but the catalytic converter stil cold that is the reason for the CO reading being higher than normal.The HC is also high this indicates a high number of missfire.this is also because car i still cold.
The next reading i had to take was when the car is warmed up.
CO:6% HC:171ppm CO2:12.8% :O2:0.08%
This result indicates that the catalytic converter is not working efficiently.The hc number has come down alot because the car is at a good tempreature and steady went into closed loop so idles better.
Next reading was at 2500 rpm
C0:39% HC:245ppm CO2:12.8% O2:0.16%
The HC number has gone up again because we increased the revs so the misfire count went up because it is at higher rpm more strain on engine.CO is still high shows the catalytivc converter is not working properly.
Next task was to make the car run rich and record reading.I did this by spraying a little carberator cleaner into the intake.
C0:7.7% HC:1800ppm CO2:14% O2:-O.O2%
The CO has still not realy improved.The hc in this one is verry high which sows a verry high amount of misfire.The O2 is verry low.this show that the car is running rich.
Next I had to make the car run lean.I did this by removing a vacuum hose.
CO:0.3% HC:1400ppm CO2:7.8% O2:9.8%
In this one the CO is good.The HC is still very high because it is running lean the missfire number is high.The O2 is realy high.This shows that the car is running lean.
I had to accelerate for a short time and record readings when CO is reading highest.
CO:4.2% HC:240ppm CO2:13% O2:0.15%
The CO at its highest reading is not verry high.This shows that the cat is working.the missfire number pretty high because rpm increased.The O2 reading is good car not running to lean or rich.
Next I had to disconnect a spark plug and ground it.
CO:15.2 HC:1900 CO2:13.7 O2:0.9
In this task the missfire number was verry high because it is only running on 3 cylinders.The CO is getting higher this indicates the catalytic converter is trying to work.
I had to disconect one injector.
CO:1.8 HC:282 CO2: 10.3 O2:5.3
Cat converter working pretty good in this test.O2 reading hig indicates that the engine is running lean because with the one injector disconected engine is not getting enough fuel
Made other changes do see diference.The changes i made was I turned the aircon on.
CO:3 HC:240 CO2:13.1 O2 0.14
Only thing that quite hig in this test was the HC but not to high.
If I did all these test on a vehicle without a catalytic converter the readings for CO and O2 will be higer because it will run lean.lambda O2 sensors has 4-5 wire because extra wires are used for signal wires.
HC indicate if the fuel is being burnt fully, you can get HC in a misfire but also if there is to much fuel rich or if there is to little lean
ReplyDeleteCO indicate rich or lean
CO2 and O2 indicate the efficiency of the combustion but also if your cat is working e.g good cat low O2 high CO2
On your first reading is that 49% or 4.9% or .49% it makes a huge difference
revving the engine up should not make it misfire but you will get high HC why?