1997 passat 1.8 petrol

What i can tell you is it the engine is running to lean air to fuel mixture should be around 14.7 to 1 air being 14.7 fuel 1 witch means you must have an air leak or a fuel delivery problem .The vehicle is to new for the fuel pump to be worn out .I would replace the in line fuel filter first.See what that dose.

run the fault codes to ensure that the EGR valve is faulty. Engine lights to not always come on unless there is something drastic going on with the engine /gearbox so that you can stop the car before damage is done.

My car was doing this and I had to get all new coil packs... Mine were replaced under recall at the dealership at no cost. If you take each code and google it, or even check a VW forum, I'm sure the members there can provide a lot more thorough information...... I have a 2001.5 Passat myself and when one thing goes out they all follow suit. I will help with some research for you and post back...... But I'd check the coil packs that sit atop the spark plugs.

You most likely have an engine vacuum leak or a defective mass airflow sensor or low fuel pressure. Read the codes with a OBD2 code reader and see what the standard codes are.

This fault could be anything from a split or perished vacumn pipe somewhere on the inlet manifold to a mass air flow sensor and i would advise that you ask a local mechanic to have a look for you to see if anything is visable from a quick look at the engine .

Combustion engines operate by burning an air/fuel mixture of about 14.7 to 1-14.7 parts air to 1 part fuel. When the air ratio goes below 14.7 parts, this is called a "rich" mixture. If the air rises above 14.7 parts, it is called a "lean" mixture.

Rich Mixture = Too much fuel, not enough air
Lean Mixture = Too much air, not enough fuel

To keep the engine running properly, the Engine Control Module measures the oxygen content in the exhaust with oxygen sensors and makes adjustments to the mixture by injecting more or less fuel.

P0507 Idle Control System RPM Higher Than Expected
P2187 System too lean at idle

Things to check:
1. MAF
2. Fuel pressure, fuel pump flow rate

Do you have cold air intake?

Run a fuel system cleaner first and reset software. Long Term Fuel Trim Additive. Max Value, Air/Fuel too Lean.

Fault symptom

Malfunction Indicator
Lamp

The engine may stop after starting, run unevenly and misfire or run
at high rpm.


On-board diagnosis

Type of
diagnosis:

Continuous

Enable criteria:

The engine has started and lambda control is active.An additive adaptation is
carried out.Cooling and intake air temperature 60°C.Fuel level at least
12%.

Fault criteria:

The additive adaptation factor is greater than 5.25%.

Diagnostic help

Diagnosis
regards:

Checking air/fuel ratio. With this DTC, the engine will be getting too much air or too little fuel.IMPORTANTA crankcase ventilation leak may be one reason as to why a DTC is set. Check crankcase ventilation function before starting regular troubleshooting.

Functions in the diagnostic
tool related to the fault:

Test value:
•O2S1 lambda
•Additive
Adaptation
•Short Term Fuel Trim
•Purge Adaptation
•Airmass Deviation
from Calculated
•Total Fuel Trim Here's a helpful link for you: http://repairpal.com/OBD-II-Code-P0171-and-P0174


You most likely have a vac leak. Hope this helps Fix Ya! Show some love with positive feedback if this brings you to a solution. Thanks Happy Hanna-kwanz-mas

The exact same set of codes have just come up on my car, the same car and year. Did you solve it? I am thinking cleaning the throttle body first, any help appreciated....

throttle may need adapted

Remove the MAF sensor and carefully clean the sensing diodes with some solvent and a q-tip. These codes are commonly caused on this car by a dirty MAF that does not see the air entering the engine so fuel is not added by the computer. Then the computer sees that the mixture is lean by looking at the exhaust gas oxygen (sensor) content and it sets a code because it can't trim fuel delivery to the correct level as the MAF signal has more authority.

This code reads "Mixture Adjustment Control" which could be O^2 sensor or even MAF (mass air flow) sensor in air intake. Your gas/air mix is not being set properly by the computer due to faulty info from engine sensors.