Greetings, newbie here. I've had this car for a few months with good luck so far. Have a CEL on the 2000 a4 Quattro 1.8 with ATW engine and I've searched the database here but need something more specific. AZone read a P1128 code for me. Where is my MAF? On the passenger side, there is a sensor in my air box (just added a new filter and saw that), under the driver's side head light there is a sensor on the outlet side of the intercooler (I guess that is the intercooler), and another sensor after the throttle body (right?) at the intake manifold. Do I just dump the $100 and buy the new MAF and assume it is the problem? I'm new to turbos so don't know my way around yet. see pix.

Thanks,
CH


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P1128 Long Term Fuel Trim mult., System too Lean.
Check for vacuum leaks.

17536/P1128/004392 - Fuel Trim; Bank 1 (Mult): System too Lean
Possible Symptoms
[ul][*]Malfunction Indicator Light (MIL) active [/ul]
Possible Causes
[ul][*]Mass Air Flow Sensor faulty[*]Oxygen Sensor Control faulty[*]Fuel Injector(s) faulty [/ul]
Possible Solutions
[ul][*]Check Mass Air Flow Sensor[*]Check Oxygen Sensor Control[*]Check Fuel Injector(s[/ul]

 

Hawk, where is the MAF on my car and what are those sensors shown in my pix?

thanks

 

I have the same exact car/engine. I got that code and it was from a leaking vacuum line. don't get the rubber and braided line at the dealer - those tend to rot and break every 2 yrs or so. Get the rubber line similar diameter at Autozone or Advance Auto parts. 8 ft is probably more than enough line, and it should be less than $1/ft.Some attachments likethe oneunderneath the intake manifold are tough to reach,but itis do-able with effort.

 

You have to remove the air filter box to remove the MAF.
Start by checking for vacuum leaks.

 

yes - check for vac leaks first. Then you might try cleaning the MAF - search for that procedure.

 

ill go with vacuum leaks and clear the code and see if it comes back

 

Aren't there several different diameter vacuum lines under the hood? I'm guessing that everything on the motor that isn't moving liquid, electricity, or has a cable inside is a vacuum line. Thus, I have multiple diameters. So, how did you buy 8 ft and get by?

CH

 

Hey Bogie, see my question on vacuum lines, since you've done the replacement before.

Aren't there several different diameter vacuum lines under the hood? I'm guessing that everything on the motor that isn't moving liquid, electricity, or has a cable inside is a vacuum line. Thus, I have multiple diameters. So, how did you buy 8 ft and get by?

CH

 

To answer your pix ?s: Thumb 1 is the connector to your MAF sensor; T2 is your MAP sensor; T3 is your IAT sensor.

Ditto on checking for vacuum leaks. Actually, there are only a couple of generic replacement lines. Your FPR hose, DV hose, etc. The other hoses that could leak are "special" hoses that come pre-molded.