2000 VW Passat code P1128

[Gregory Vermillion]

My daughter has a 2000 Passat that she purchased 4 months ago and it has a problem with a check eng lt that keeps coming on and she took it to the dealer and they did a diagnostic check and siad the fwd 02 sensor was bad she had that replaced and still gets the light and when I download the codes she has a P1128 code. The books really dont say how to troubleshoot this code and the car gets the herky/jerky sometimes on decelleration but they dont seem to be related in any way? Can anyone give me some advice on possibly troubleshooting this myself. I have a scan tool and am very mechanically inclined.
Thanks for any Help
Greg

[boschmann]

That is actually a code that the long term fuel trim is too lean. The most common cause of this code on a 2000 (both V6 & 1.8t) is a bad mass air flow meter. Other possibilities are vacuum leaks & oil dilution. Which engine?

[Gregory Vermillion]

It has the 1.8T turbo engine, any ideaas on the herky/jerky movement felt on the deceleration? it has the 5 speed transmission in it and noticed the other aticles basically describing the same simptoms, but sounds like they have automatic transmissions, mabey its the same for the standard transmission as well?

[boschmann]

The 1.8t is less likely to lose a MAF than other engines. I would first do a very thorough look at the vacuum hoses, particulaly the larger (1/2") ones hidden under the intake manifold. They can be hard to find, but r very common to fail.

[Wyatt88]

I have the same problem with my volkswagon passat its the 1.8t 5 speed and my check engin light comes on every time i start it but the gerking only happens when i accelerate and when my car is cold in the mornings or if i just started it it makes like a werid noise until the car warms up but the noise isnt like a lose belt its different like it goes with the rpms of the car and is more like a loud pulsing sound

[Everman]

I've been battling the same problem. I've been following the advice offered in this older thread: http://www.automotiveforums.com/vbul...d.php?t=359851

I thought I had it kicked when I cleaned out the air screen in front of the air box. The light went out a few days after I did that.

But then a week later, it went on again.

My next step will be to replace the air filter and clean the MAF sensor with this stuff: click

It'll be a while before I know if it works or not, but I'll update if it does.

[corey7695]

to the guy with weird noise in engine compartment when cold...check your air injection tubes, there made out of corrogated plastic and break often causing you to hear air injection pump whirring when cold. air injection pump is in fender well in front of passenger tire, also car being jerky on acceleration is a common sign of spark break down, either spark plugs or coil packs are most likely to blame, just replaced my coil packs and it fixed problem. still battling code1128 but have a good idea that it's my down stream oxygen sensor.....will get back online when i fix it hope this helps