Maf - 986 Forum - The Community for Porsche Boxster & Cayman Owners

fab · 03-13-2006, 03:21 AM

How do you know when you have to replace your MAF?

Fab
00 Boxster Tip Blk/Blk

l8braker · 03-13-2006, 04:05 AM

Your check engine light will come on.

blinkwatt · 03-13-2006, 07:51 AM

Most of the time when you have a bad MAF there are several simptoms;
1. A bouncing idle(big or small)
2. Codes P1123 and P1125 from the CEL
3. Hesitation when you step on the gas

nautiquelfe · 03-13-2006, 08:06 AM

Are there preventive measures that one can take? I recall seeing steps about cleaning the maf. Does this prove to be a worth while project?

MNBoxster · 03-13-2006, 09:32 AM

Quote:

Originally Posted by nautiquelfe

Are there preventive measures that one can take? I recall seeing steps about cleaning the maf. Does this prove to be a worth while project?

Hi,

All the Pros state not to clean these. This is because the MAF Porsche uses incorporates a Hot Film, that is, a conductive film (possibly Mylar) through which a reference current is passed.

Cleaning with a solvent could cause damage to this film and interfere with this reference current. My inclination would be to use only pressurized Air, such as the Spray Cans used by Photographers.

The problem is you could clean it sufficiently to get it beyond the fault threshold, while still signalling an inaccurate Air Mass to the DME. If this happened, you'd never know since there would be no MIL, but the DME could be using an inappropriate A/F MAP because of it and allow the Engine to run Richer or Leaner than ideal. This could have negative long-term effects to the Engine longevity and/or the Exhaust components, the Cats in particular.

That said, given the expense of this module, I'd probably attempt to clean it first, but if there were any question about it's post-cleaning performance, I'd bite the bullet and swap it out. Hope this helps...

Happy Motoring!... Jim'99

PorscheDoc · 03-13-2006, 01:39 PM

Cleaning the maf with pressurized air is an absolute No No, that will almost always kill it for good.. I have had a little luck using CRC QD electronics cleaner, and letting it air dry. I have heard the dealers are using carb cleaner to clean them, and I have talked to a couple of guys who have been using the same thing with good results.