I have a couple of questions about how the o2 sensor works with the computer.
First, during open loop the primary o2 sensor is ignored, right?
Would unplugging your primary o2 sensor get the car to run in open loop or would it affect my performance?
Does the second o2 sensor affect performance if its bad?
The reason i ask is because when i first start my car and it begins to run in closed loop it reads that the car is really rich and i lose all power. This happens until i floor it and it goes away or i can just let it work its way out..
My last question is, what brand o2 sensor should i use? I have a bosch in there, but i think that is the problem. Without going to the dealership, I can get Standard, KEM, and Borg-Warner o2 sensors. I am also pretty sure i can get the ac delco one. Also, I have a header and full exhaust if that affects anything.
The 1st O2 sensor can reduce performance, but the 2nd will not.
Better to use AC Delco sensors and spark plugs. Bosch sensors and plugs suck for J-bodies.
Before you start the car in the morning.. try steping on the gas pedal twice then start the car.
97redGT wrote:I have a couple of questions about how the o2 sensor works with the computer.
First, during open loop the primary o2 sensor is ignored, right?
Would unplugging your primary o2 sensor get the car to run in open loop or would it affect my performance?
Does the second o2 sensor affect performance if its bad?
The reason i ask is because when i first start my car and it begins to run in closed loop it reads that the car is really rich and i lose all power. This happens until i floor it and it goes away or i can just let it work its way out..
My last question is, what brand o2 sensor should i use? I have a bosch in there, but i think that is the problem. Without going to the dealership, I can get Standard, KEM, and Borg-Warner o2 sensors. I am also pretty sure i can get the ac delco one. Also, I have a header and full exhaust if that affects anything.
The car runs in open loop until the following conditions are met-
-car on time is above 60 seconds
-the car has reached operating temp
- the O2 sensor has heated up
Once those are met it enters closed loop.
The car will run rich until it heats up, the engine is colder, it needs more fuel.
Unplugging your O2 sensor wouldnt be one of the dumbest thing you could do.
How would the computer know how much fuel to send into the engine, the O2 sensor tells it if it running rich or lean.
O2 sensors can hurt performance gas mileage, mileage up to 30%. O2 sensor that are bad, you wil most likely get a hesitation especially when cold.
Good luck.
PS only use parts from GM, Autozone and @!#$ all nothing but junk parts
- 2004 Cavalier - 124k, owned since new
unplugging your O2 sensor temporarily will NOT hurt anything. If you are already running rich once in Closed Loop, then unplugging it will just put the computer back in Open loop. In your case, Open loop may be better if your sensor is causing a rich condition. In Open loop your car will run off of the base set of stock fuel settings. It will be a bit richer then with a good working O2 sensor, but it will not be as rich as a cold start. Your coolent temp sensor determins how much fuel is sent to your engine during a cold start. Anyway my point is, unplug the primary O2 and go for a drive and see if it helps your condition. If it does, I would start by replacing the O2. I drove one day with my o2 unplugged, and it did not even trigger a Service engine light.
Xian G wrote:Before you start the car in the morning.. try steping on the gas pedal twice then start the car.
And that is going to accomplish absolutely nothing on a fuel injected engine.
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John Leahy
'01 Cavalier Z24 - 5Speed
MaxThrottle.Com - All makes/models car forum! Everyone is welcome!
Ok, unplugging the o2 worked, the car runs in open loop and i don't have any problems. So, i ordered an ac delco o2 from murrays (it was like $40) it should be here in a couple days.
