Hi guys,

The same problem I had last year came back in the last few days. The o2 sensor is giving up.

Like last year. The problem started when it got very cold (-20F). Last year I was running the stock o2 sensor. This year I have a PLX M-300 wideband with the wideband o2 sensor feeding the stock ecu.

What happen is since it got really cold. The o2 reading are VERY lean while in fact the car is running extremely rich. I didn't change anything into my fuel settings.

The problem is it does not go away when the temperature get's warmer. It stays like that until I change the damn o2 sensor. So until I do, the car will only do ~120miles on a full tank of gas and it's also very jerky and misfiring.

Now what could be causing this problem? Is it the o2 sensor itself? Or is it another problem that cause my car to run super rich when it's cold which then damage my o2 sensor? Could it be the injectors that can't properly work when it's extremely cold? Or the fuel pump? of the fpr?

I have RC500 injectors with a Walbro 255lph fuel pump and a stock fpr.

Please help me. I need to fix this damn problem. Don't tell me to do a search because the only thing that will come up is the topics I did last year which nobody answered.

Thanks,

 

If the car is running that crappy I'm guessing there is a CEL?

 

The check engine light flash this one:

1- Oxygen Sensor "A" (Primary)
Defective circuit or unplugged / defective sensor

The airbag light flash these:

16- Fuel Injector System
Defective circuit or unplugged / defective injector

17- VSS (Vehicule Speed Sensor)
Defective circuit or unplugged / defective sensor

61- Oxygen Sensor, Heated - Sensor 1 (Primary)
High Voltage, low voltage, or slow response

Why is my check engine light flashing one code and my airbag light flashing the others?????

 

The engine light is the only one that will tell you the codes for the engine...the airbag light is for the SRS system. Chances are if it is only throwing O2 codes then that is the only problem. You said taht you were using a PLX wideband? Are you using the output from that to give the ecu a signal?

 

Yes I do.

Something tells me the o2 sensor is not the problem. Yes I get a check engine light for the o2 sensor but that's only telling me the o2 sensor isn't working properly NOW. What caused the o2 sensor to not work properly is what I want to know.

Just changing the o2 sensor wont solve the problem. I know I changed the o2 sensor 3 times last winter. Lasted a few weeks until another cold day. Then the problem came back again.

 

Very rich running conditions can damage an 02 sensor, spark plugs as well.

 

I know.

What I need to find out is why my car is running so rich when it's extremely cold.

 

ttt

Still need help.

 

It will run richer at part throttle in the cold or when the ecu is in closed loop. It is particularly true if your car was tuned in warmer weather. In closed loop the sensors see more oxygen so they signal the ecu to add more fuel.

However at WOT it will tend to lean out.

I think you may want to have your part throttle retuned for the cold weather. Lean it out.

Lots of guys I know run 2 chips, one for winter one for summer. I'm assuming you have hondata.