Definition of error code P and P – System too Rich (Bank 1 and Bank 2) . Read emissions expert information and diagnostics for fault code P and. Diagnostic Trouble Code (DTC) P Fuel Trim System Too RichDiagnostic Trouble Code (DTC) P Fuel Trim System Too Rich – United Kingdom | BBA. The fact that it’s throwing that code means that it’s trying and unable to adjust sufficiently to keep the air/fuel ratio correct. 2 is easy to check-.

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When the air ratio goes below If the air rises above When these adjustments become too large, a fault code is set. When a vehicle has the fault code Dtv and or P, it means that computer can no longer automatically adjust the mixture between air and fuel. Code P applies to Bank 1 and P applies to Bank 2. Code P mainly applies to V6 or V8 engines because 4-cylinder engines generally have only one bank, though there are a few o0172. Some of the high performance 4-cylinder and straight 6-cylinder engines such as those in BMW and Lexus split the cylinders into groups of two or three and call them separate banks.

When the code says that the Fuel System is “too rich,” it means that the computer has been subtracting more p01722 more fuel, which is called Long Term Fuel Trim.

Ideally, the Long Term Fuel Trim should be close to 1 to 2 percent. When a code P is set, it means that the Fuel Trim is anywhere from percent to as low as percent compensated. When this happens, the computer knows that there is an improper condition in the control of the Fuel System. Then check the freeze frame dfc for the p172 to see which range s failed and what the operating conditions were. Before we get into the main causes of P, let’s explore why this code matters.

CO pollution, which is poisonous and helps create ozone, is caused xtc vehicles that are running too rich.

A rich condition can also p072 misfires from “overfueling” too much fuel for the Ignition Spark to burnwhich puts raw fuel HCs into the atmosphere. When you are driving behind a “rich” running car or truck, it can smell very bad, somewhat like rotten eggs, and make you feel dizzy. This is caused by the Catalytic Converter consuming too much dtv part of vehicle fuel. However, it should be noted that a “rich” running engine can also have little or no smell, since CO itself is odorless.

P is not an Oxygen Sensor problem. Before a P code is possible, the computer first ran a series of tests to validate the readings from the oxygen sensors. Since the oxygen sensors passed their readiness tests and didn’t set any codes, the computer then looked to the Fuel Trim adjustment. When the computer determined the air-to-fuel mixture to be too rich, it dtx set the P code.


Always check to make sure that there is not a PCM software update due or available. Often, as the vehicle’s engine wears, the PCM’s Fuel Map software inaccurately compensates for this condition. The fuel mixture grows rich and eventually, the code sets.

Essentially, this means that the Air Flow Sensor is telling the computer that much more air is entering the engine than actually is. Based on this large amount of air entering the engine, the engine computer or PCM sprays more fuel into the combustion chambers. Since the oxygen tdc are telling the computer that less fuel is needed, this causes confusion in the computer because the Mass Air Flow Sensor is still saying there is too much air and the Oxygen Sensor is reporting that the mixture is still too rich.

The computer tried to compensate, but since resolution is impossible, it sets the code. It is important to restate that the Oxygen Sensors are accurate—the fuel mixture is too rich. In this case, the Air Flow Meter or Sensor is inaccurately reporting the real amount of air entering the engine. There is a very effective “truth test” for any P01172 Air Flow Sensor.

P0172 OBD-II Trouble Code: System Too Rich (Bank 1)

Start the engine, let it idle, dtv then check the Barometric Pressure reading on the scan tool data. If the reading is about These conversion tables will help. When the Mass Air Flow Sensor sees this Barometric reading, it adjusts its Air Density table and then “over reports” the actual amount of air entering the engine. Sometimes the Air L0172 Sensor and the sensing wire get covered with dirt, dust, or oil residue, which can also set a P Cleaning the sensor might hold off problems for a while, but eventually, the MAF sensor should be replaced.

Always make sure the Air Filter and its enclosure are dirt- dust- and oil-free. If you clean and replace the p01772 and its enclosure as needed, you will ;0172 the new MAF from failing. Get an Estimate Find a Shop. Was this cool or helpful? System Too Rich Get diagnosis and repair information for trouble code P The vehicle may have trouble idling, especially when warm or when sitting at a stoplight.

Unburned droplets of raw fuel that smell, affect breathing, and contribute to smog CO Carbon Monoxide: Check the MAP reading and then do a manual vacuum reading.

An engine needs to have at least 17 to 18 inches of vacuum in order to run properly. Mechanical engine problems will cause a low MAP sensor reading because engine vacuum is low or erratic. If the engine has a mechanical misfire from valve train problems or weak cylinder compression, it will send puffs of oxygen into the exhaust system.

This will cause the Oxygen Sensors to receive false “lean” readings high exhaust oxygen content. A defective Oxygen Sensor can sometimes cause a P If p01772 Oxygen Sensor heater element only works intermittently—well enough to pass the readiness test, but fails once the car has been driven for a while—the vehicle will go into “open loop. Be sure to verify proper Fuel Pressure under various driving conditions.


An inaccurate Coolant Temperature or Air Temperature Sensor p0712 cause a rich condition because they will report that the engine is still cold, which will cause the PCM to keep the mixture rich long after the engine is at proper operating temperature.

A Thermostat stuck in the open position can mechanically cause a code P, especially in cold climates. The engine won’t warm up, preventing it from going into “closed loop” fuel control. Ignition misfires, like mechanical misfires, cause puffs of oxygen to keep hitting the Oxygen Sensors. Since the sensors will think the mixture is running lean, the PCM will add fuel to the mixture. A worn or stuck wiper in the Throttle Position Sensor will tell the PCM that more power is being requested by the operator.

If the vehicle is not hoisted properly, the fuel return line can be pinched, causing a high Fuel Pressure condition.

P – Meaning, Causes, Symptoms, & Fixes – FIXD Automotive

Always verify Fuel Pressure for any code P Shorted Fuel Injector windings can cause the injectors to spray too much fuel, causing a rich condition.

Be sure to “Ohm check” the injector winding resistance as well in order to verify that it’s within specification. By VisitorFebruary 16, I have a Ford Taurus and the engine light is on. I have codes po, and pop up. I was told that the oxygen sensor, the cam sensor and the fuel cap could be the problem. By VisitorMay 15, My Honda Civic EX threw the rich code and it turned out to be that my friend installed the timing belt off by 1 or 2 teeth. By Heatman72June 06, Replaced all O2 sensors because of excessive buildup, crank sensor, timing belt with water pump, motor and transmision mounts, radiator leakthermostat, and plugs wires cap and rotor.

The car also lacks power from a stop but after it is going a bout 15 or 20 MPH it gets with it.

Valve cover and intake gaskets are all new. Wondering how one bank is too lean and other is too rich.

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