Dankrohn

1999 A4 2.8 Quattro

Hey guys,

I have an HPS Cold Air Intake and for a while now my engine has been idling very rough and acceleration has been lagging, to say the least (stalling out by itself even). I was looking around and after some experimentation, I noticed that when I took the filter (just the filter, not the piping) off, it idles extremely smoothly and acceleration is much better, leading me to believe that the filter (even after cleaning it and re-oiling it) is starving it of oxygen. One would think that a Cold Air Intake would IMPROVE flow, but not in this case. Does anyone have any experience with this? Thanks.

Dan

99a4turd

maf try to clean it if that dont work replace it open air filters kill maf's

xsrfsno225x

you can't use filters that require oil with MAFs. Guaranteed its dead. don't even bother attempting to clean it. You need a new one.

600whpA4

Sorry but that is complete BS. Just because the filter is oiled doesn't mean the maf is going to read the air flow different then when the filter has been removed completely. Something on the filter is causing a drop in air flow at the center of the maf.

To me it almost sounds like the filter being used has a dead spot right in front of the maf. If you are using a filter that mounts right to the MAF body or just in front of the maf you can NOT use a maf that has a inverted cone.


Dankrohn - Do you have a picture of the HPS kit?

Dankrohn

The funny thing is, it IS in fact an inverted cone, BUT it't not directly to the MAF, although its about an 18" short ram, so I'm not sure if the inverted part still has an impact. I'm tempted to try another filter, although I dont imagine that it will do much good. I've attached pics of the current HPS filter

xsrfsno225x

Before you jump up and down stating the oil won't cause the MAF to die due to constrained air flow, get your argument on the same page as me. I'm not referring to the airflow. I'm referring to the contaminant (oil in the case) being sucked onto the sensor surface of the MAF. The oil doesn't make it read it wrong temporarily, it ruins the sensor
Maybe his situation is constrained airflow. But generally speaking oiled filters kill MAFs.

Dankrohn, do you have a CEL? Either way, plug into vagcom and look at MAF reading. It should read about 3 g/s at idle.

Dankrohn

I do have a CEL, but i had it scanned last week, at which point i found out both my rear O2's are bad AND i had misfires on 2 cylinders that come from the same coil, but nothing else came up. I can try to get to a vagcom. How would I know if the MAF is bad? Thanks again guys.

xsrfsno225x

you can tell if the reading if different than 3 g/s via vagcom

or unplug the maf and see how it runs, if the problem goes away then voila, its your maf. If the problem stays, then we can talk about other things. i also recommend fixing the issues associated with the CEL. Those codes could very well be the culprit.

600whpA4

I know exactly what you were talking about and it is still complete BS. Who the hell would even think that air flowing thru a maf would damage it when thats what it is made for.

I am 43 years old not 14 years old and have been been a Audi World member since 1999. lol

I have been running K&N oiled filters since I got one for my 2G Elipse back in 1995, then my A4 and both my Titans. All of them have a MAF sensor.

The only time an oiled filter is going to cause a maf to die is when the USER ends up soaking the filter with oil after they clean it. Cant exactly blame that on the filter.

600whpA4

The inverted cone could be causing most of all the air flow to be sucked up against the sides of the pipe causing the maf to read much lower then it does when you pull the air filter off.

Might as well just replace it with a standard flat closed end filter or one with a flat filtered end.