[mism]

Hello, I am getting intermittent check engine and fault code P2188. I checked the code and it is System too rich at idle speed (bank 1). There is no impact on the engine running or the performance of the car when the light comes on and when driving.

When I clear the code it may not come back for sometime, but every now and again the check engine light comes on usualy when I stop at the traffic lights.

I also noticed that the code and check engine light only comes on when fuel level is below 3/4. I did an experiment when for about a month I kept topping up the tank so the petrol level didn't go below 3/4 of the tank and the CEL never came on during that time.

Has anyone come across similar issue?
I have spoken to couple garages, but they say as it is intermitent issue, they cannot help.

 

[TheAntman]

The air/fuel ratio is monitored by the O2 sensor in the exhaust - since there is a direct corelation between oxygen in exhaust gases and the oxygen available for combustion - so this is how the vehicle measures it.
As it's intermittent, it's going to be a challenge to pin it down, but there are a few checks you can do to rule some things out.
I'd have a look at the O2 sensor. Check the wiring and maybe think about taking the sensor out and giving it a clean.

 

[PURPLE_2L_LX]

£20 ish OBDII reader with Forscan software/app for your laptop/phone etc. Monitor the O2 sensors
and the MAF/MAP sensor see if they get erratic at certain temperatures.

 

[mism]

The air/fuel ratio is monitored by the O2 sensor in the exhaust - since there is a direct corelation between oxygen in exhaust gases and the oxygen available for combustion - so this is how the vehicle measures it.
As it's intermittent, it's going to be a challenge to pin it down, but there are a few checks you can do to rule some things out.
I'd have a look at the O2 sensor. Check the wiring and maybe think about taking the sensor out and giving it a clean.

Thanks. I will have a look at the O2 sensor this weekend.

I was also thinking it could be something to do with the fuel pump or presure in the fuel tank as the fault only happens when there is less then 3/4 fuel left.

 

[mism]

£20 ish OBDII reader with Forscan software/app for your laptop/phone etc. Monitor the O2 sensors
and the MAF/MAP sensor see if they get erratic at certain temperatures.

I will need to find one that works on iOS as I don't have any Windows or Android devices.

 

[PURPLE_2L_LX]

Tunnel Rat sell them you just need the WiFi one for iOS devices. App in the store if you want to try it first.
Not sure whether its a trial or need to buy it right away on the Apple store. With Android there is a light/lite?
version with limited use to try before buying the app. It was not expensive £3 or so? £20 ish for the
OBDII reader.