Ordered a replacement MAF for my 2003 F150 V6

The old MAF had #F6DF-12B579-EA
The new MAF has #F6ZF-12B579-AA

Is that number difference not relevant ? Or did I get the wrong MAF ?

 

They are interchangeable. The new one fits 1997-2008 4.2.

 

Thanks for the quick reply.

I installed the new MAF and within 20 miles of driving I got PO171/PO174 - lean mixture on banks 1 and 2.

The freeze frame data is:

Fuelsys 1--CL
Fuelsys 2 -- NA

Load Pct -- 62.0
ETC-- 149

Shrt FT1 % --4.7
Long FT % -- 28.1

Shrt FT2 % -- .8
Long FT2 % -- 24.1

RPM -- 1417
VSS (MPH) -- 23

Vehicle is running smooth right now.

How can I test to see if the new MAF is defective ?

 

Look up in the fsm. There is a procedure for testing it. Uses a dvm

Also, did you unplug your battery? Basically doing a hard reset so the computer can update to the new hardware if needed?

 

I didn't unplug the battery. After replacing the MAF, I cleared the codes with the code reader. The Chilton manual says not to unplug the battery and just use the code reader, so that's what I did.

Is there any difference ? Is it too late to do that ?

 

Disconnect the battery so it can relearn.

 

It was worth a try.....

Disconnected it for about an hour. Took it for a test drive and CEL came on in about 10 miles. Same problem, similar freeze frame data.

Truck still starts easily and runs smooth. So I am still thinking it's not a vacuum leak which typically causes the engine to run/idle rough.

As I understand it, possible reasons for a lean code are:
-low fuel pressure
-vacuum leak
-bad MAF
-bad PCV
-bad O2 sensor

I did come across some information which said if the lean codes appear other than at idle, then there is likely not a vacuum leak. Mine showed up around 23 mph speed.

The fuel filter was just changed about 5,000 miles ago. So, I'm less inclined to think it is a fuel pressure problem. The O2 sensor is a remote possibility.

I'm thinking it is the MAF or perhaps the PCV. Since I just replaced the MAF, the coincidental timing of new lean codes is highly suspect to me.

I have a new PCV coming in, so I can replace that. The vehicle is around 95,000 miles and is probably due for a new PCV anyway.

 

Have you tested the maf? If not, test it.

 

That's next on my list. I haven't quite figured out how to do it.

I did just finish a quick vacuum test on the engine. The gauge was rock steady in the engine normal zone.

 

Okay, this is odd, I did a voltage test on the power plug to the MAF and only find 5.3 volts going to the MAF . It should be 12 volts. So, what could be restricting the power to the harness ?

 

Is this a genuine OEM MAF, or is it aftermarket?

 

The MAF is a reman. aftermarket. The dealership wanted $600 for an MAF. Parts stores wanted $100 - $200 for reman. aftermarket MAF.

The voltage problem I have is the power going to the MAF, so the MAF has no part in this problem.

 

Fsm has maf testing procedure.

 

$88.79 for OEM.

https://www.rockauto.com/en/catalog/...ow+sensor,5128

 

I would test it, but some people like throwing $ :dunno: