MAF cleaning?

[My Sprinter's A Lemon]

Hi again, a search brought up little....

I would like to clean the Mass Air Flow Sensor. I have code P0100 - Mass or volume air flow A circuit. My understanding is that a dirty MAF sensor can be a symptom triggering the code. I thought it would be an easy clean, but I have discovered that the wires are hidden inside the tube and grills enclose the tube preventing any access.

My van runs great but it appears to be running rich and excessive exhaust is present, kinda gray and transparent out the tailpipe and stinks up the area in seconds.

I cleaned the EGR which was black with soot, replaced the oxygen sensor which was also black with soot, and replaced the fuel filter and battery.

Any thoughts?

Thank you.

 

[Midwestdrifter]

Do you have a subcode? That would help. There are 7 different subcodes. Some are wiring, some are implausible signal, some are voltage related.

You can remove the airbox cover from the van, and spray the MAF out with cleaner. Even with the plastic guards in place. Check and clean the electrical connector. Also inspect the harness for possible chafing or damage.

A dirty O2 sensor can cause some MAF codes.

 

[My Sprinter's A Lemon]

I had replaced the old dirty O2 sensor with a new one. I went ahead and sprayed the MAF best I could. I get no subcodes. I now get a window that states "The signal from the hot film MAF sensor is needed to regulate exhaust gas recirculation."

Incidentally, after doing all of these maintainance items, I now have like 20 codes, from radio to abs to tires, KI cluster, everything!

 

[autostaretx]

You did, of course, read the MAF pages found here? http://diysprinter.co.uk/reference/T1N_service_scans/

They detail what's going on inside the MAF, and may help interpret that message.

--dick (who wouldn't casually spray it, but that's me)
((attack it with a toothbrush? Lemme think on that...))

 

[CJPJ]

The MAF is appropriately just downstream of the air filter and should remain clean. If it really needs a cleaning, then first fix the thing/things that made it dirty.

 

[rjc3]

You can buy MAF spray cleaner at any parts store. CRC offers it in a grey can.

 

[Midwestdrifter]

MAF sensors are hotwire types. The area around the wires, or the wires themselves should never be physically cleaned. Only a solvent rinse is acceptable, and it must be done carefully.

What code reader are you using? Cause you should be able to get a subcode with a good reader. That will dramatically narrow down your troubleshooting efforts.

 

[My Sprinter's A Lemon]

I had read up on the subject of MAF cleaning and understood that one must not touch the wires but instead to just spray the MAF cleaner on it and wait for it to dry. However, there is no direct pathway to spray the delicate wires as the wires appear to be protected on each side by a plastic piece. So I had sprayed MAF cleaner through the grills, tilting it, hoping the wires would catch some of the dripping cleaner on it...that's the best that can be done for the MAF apparently.

I'm using the AP200. I didn't notice any subcodes for this but I am new to this scanner, and scanners in general, so I will try again and see.
After rereading the quote I offered up in Post #3, it was just some extraneous info the scanner popped up and not of any concern to the issue at hand.

Thanks for the responses. I'll keep working on it.

 

[SprinterFixYouTube]

I have cut open several maf sensors both original and aftermarket. I'd hate to be the bear(er) of bad news but original bosch maf sensor use a hot film that is impossible to spray, and even if you were to carefully cut the thing open and spray it, it would most certainly wreck it (at least according to multiple tdi forums who have looked at it under microscopes and done tests). Funny enough if you compare the originals to aftermarket sensors. the aftermarket ones (at least the cheaper aftermarket ones) at no surprise use the hot wire technology which is easily exposed and can be cleaned with the maf cleaner available in store. so to sum things up: fake ones can be cleaned but bosch original ones cannot, at least 2004+ sprinter models this is true for, I dont know about the older ones but according to bosch they have been using hot film since the 1980s.... I'll have a video going into more detail on youtube.

 

[lady3jane]

'02 612.
Guess I already posted this somewhere.
Stuck entire assembly in a bread bag with half a cup of gasoline and gave it a good shake. Didn't solve the black smoke on acceleration problem.

Tightening all the hose clamps on the air intake system did.

L3