Is a high AFR rich or lean?
When an air/fuel mixture has too much fuel, it is rich. When there is not enough fuel, it is lean. An AFR higher than stoich = lean. An AFR lower than stoich = rich.
Is 12 AFR rich or lean?
ACCELERATION: 12 AFR Best performance for most vehicles is around 12 AFR. Going too rich will cause a sluggish roll-on to get up to speed.
What happens if engine runs lean?
In combustion engines, “running lean” goes beyond using gas efficiently. In effect, that status makes the engine perform with less gasoline than it needs to operate properly, and it increase the amount of friction between the engine’s moving parts. Running lean can damage an engine.
What does rich mean on a Subaru WRX?
A rich condition indicates that the air fuel mixture has too much fuel or not enough air. This would be the opposite of a lean condition, which’ll throw P0171. The P0172 code on a Subaru WRX will often be thrown if the fuel injection system is not operating properly. Typically the code will be triggered by a rich condition in the engine.
What causes a Subaru WRX to misfire at idle?
Misfire – If the air fuel mixture has gotten too far from factory specs, this can cause the WRX to misfire. Idle Issues – With the air/fuel mixture altered, the vehicle can idle erratically as the computer compensates to keep the engine running. Exhaust Smell/Color – Depending on how rich the motor is running,…
What is the trouble code on a Subaru WRX?
A common trouble code with the Subaru WRX is P0172. This code number references a number that is given to you when you plug your car into a OBDII scanner. It’s not the most complicated OBDII trouble code to diagnose. It is also one of the most common.
What does trouble code p0172 mean on Subaru WRX?
A common trouble code with the Subaru WRX is P0172. This code number references a number that is given to you when you plug your car into a OBDII scanner. It’s not the most complicated OBDII trouble code to diagnose. It is also one of the most common. It means that the motor is running with a rich condition.
Are there any air / fuel ratio sensors still around?
Despite being around for over a decade, it seems to me that air/fuel (AKA wideband) sensors still have an air of uncertainty about them in the automotive aftermarket. Weird data PIDs, they don’t switch like regular O2’s, and some have SEVEN wires?
What are the symptoms of a lean running engine?
A lean running condition may manifest in driveability symptoms that have not (or not yet) triggered a DTC. Customer complaints may include symptoms such as decreased fuel economy, lack of power, hesitation on acceleration, backfiring through the intake, overheating, weird smells or other problems.
What should fuel trim correction be for lean running engine?
The manufacturer selects a level of fuel trim correction (in this case, a positive percentage) beyond which a code will be set. Depending on the details, this level may be as low as 20% or as high as 50%. Again, depending on the details]
What’s the ratio of air to fuel in an engine?
You can think of rich as meaning too much fuel for the amount of air or as not enough air for the amount of fuel. For conventional internal combustion gasoline engines, the stoichiometric ratio of air to fuel is approximately 14.7:1 by weight, which works out to about 9000:1 by volume.