16514 - Oxygen (Lambda) Sensor B1 S1

[skreel]

I have a 2000 TT 1.8L Quattro. My check engine light came on and the engine doesn't seem to idle right. It seems louder and more rough then it should to me. It also seemed to stutter a bit when starting, dipping down in the RPMs to where it almost stalls. So I bought a cable to connect my laptop and downloaded the shareware version of VAG-COM. It reported the following fault:

17544 - Fuel Trim: Bank 1 (Add): System too Lean
P1136 - 35-00 - -

I cleared the code and started it up. It seems to start better then before, but it still doesn't sound right or feel right. I let it idle for a while and then plugged the computer in again. The check engine light didn't come on, but the computer reported the following code:

16514 - Oxygen (Lambda) Sensor B1 S1: Malfunction in Circuit
P0130 - 35-10 - - - Intermittent

I've tried googling to see what people think, but I couldn't find much out there. Does it sound like I should just try replacing the oxygen sensor that the DTC is referring to? Or is there something else I should check?

Thanks in advance,
Scott

[skreel]

The car seems louder than normal. I figured the running lean code could be a result of the malfunctioning O2 sensor, but I also thought that the fuel injectors could use a little cleaning. So last night I put some fuel injector cleaner in. Started the car up and after a while the engine seemed to quiet down substantially. I decided I would reset the O2 sensor fault and let it idle for a while to see if any fault codes would appear. No fault codes appeared, but it still seemed like something was up.
So this morning I thought I would drive it around the block a little. The car stalled the first time I tried to start it up. Other than that, the car seemed to drive fine. It didn’t appear to lack power anywhere, but I did not push it too hard since I don’t know what’s wrong. It is still louder than normal though. The higher the RPMs the louder it is too. Also, a few times when I would switch from second gear into third and the RPMs would change the car would make a slight popping/spitting sound. I'm assuming it's backfiring... I had to get to work, so I did not check for fault codes. I will this evening.
What would cause the engine (I think it’s the engine) to run louder than normal and the popping/spitting? Could the O2 sensor make that huge of a difference? I do plan on replacing it, but that can’t be causing all of the problems could it?
Any help would be greatly appreciated!

[a8 tech]

air mass meter causes this and it wont store a fault for air mass,look in measured value block 32 anything above 10% INDICATES AIR LEAK HENCE LAMBDA REACTION TO FUELING.DONT ERASE THE FAULT MEMORY AS YOU WILL LOSE THE DATA IN MEASURED VALUE BLOCKS TO DETERMINE THE CAUSE AudiWorld Forums: Fuel Trim Information (Running Rich or Lean?) EXPLANATION OF FUEL TRIM

[skreel]

Unfortunetly I already erased the fault memory. I'll drive it around the block a bit to hopefully collect enough data and have it throw the code again (without braking). Is there an easy way to check for air leaks?

I tried unplugging my mass air flow sensor while the car was running. The car seemed to idle the same whether the mass air flow sensor was plugged in or not. This doesn't seem right to me?

[a8 tech]

Well i think you have answered your own question and the airmass is defective,but this is up to you i would refer to audi dealer for confirmation,i am not tying to offend you but i dont know how qualified you are at engine management fault diagnosis.

[skreel]

No offense taken. I'm not qualified at all. I don't know a whole lot, but I'm try to learn... and you learn from doing. Thus, I'm trying to fix the problem my self. I'm just trying to get as many opinions as possible. A buddy of mine told me that car's go into a sort of safe mode when sutff goes wrong and he swears that it's all the O2 sensor... and that is why unplugging my mass air flow sensor did nothing. Whether this is true or not, I don't know...?