2001 Volkswagen Other

I bought a used 2001 Jetta GLS 2L WITH 105000 KM. I had the check engie light on, I brought to my garage and the code read PO171 fuel trim bank 1 system too lean, I had the mechanic reset the computer, I drove for 2 days and the light came back on, after 3-4 days of driving the light went off abd have been drving for 2 days now without it being on.

I know that this can be as simple as a vacum leak just changing the tubing that recirculates the oil fumes or it could be a mass airflow sensor or the o2 sensor?

However I am confused when the light went off?

Should I disregard the problem until the light comes on or can someone tell me exaclty what the problem is. I know I can have a diagnostic run on the engine, however this can take both time and money to find the exact cause.


October 20, 2007.

Od clean the maf. It might be just corroded enough to prevent the light from going on but still corroded enough for it to not work properly

Oct 20, 2007.
Vw has a tsb for this and i've changed a few. The airflow meter (maf) needs to be changed. A new one from the dealer, iirc, is around $170. Cleaning it, if it works, is a temp fix.

Oct 22, 2007.
You can get a MAF Sensor from your local Auto Parts store for 150.00 (without core) and it goes down to about 119.00 after you give them back your old one. MAF sensors are a common failure on VW's, among several other issues. VW has issued many extended warranty's on most of the parts that fail most often, so check your warranty status vs. a list of extended warrantys posted by VW. Google them would be a good place to start. A list of common issues with VW as well. Luckily the MAF sensor is an easy repair, lasting a whole 10 minutes at max. *use caution when handling the sensor, it is very delicate: clear the ECM of the trouble codes before starting the car after replacing any sensors that have malfunctioned, failure to do so could seriously impact the driveability of your vehicle!*

Nov 18, 2007.