Yeah I also checked out my maf and cleaned it. Now the highest reading I got was 171g/s. Quick question for you, have you ever changed your maf. One thing I have discovered doing all my research on tune companies was that the 03-04 use a different maf which allows more air flow than our truck needs. Per the tornado systems page our ecu has never been adjusted to get the most out of this maf. So the maf should take the extra air but will have to be tuned with the ecu in order for the computer to recognize the extra air.

http://www.tornadosystems.com/produc...er-maf-sensor/

 

Huh, I totally missed that the first time I read that page. I thought they were saying the 99-02 had a smaller MAF housing than the 03-04, which is also true. I'm surprised to find that they made a third and larger yet size for the P38.

Nope, I've never changed my MAF, and as far as I know it was never changed by any previous owner when I got it at 120k (I'm at 143k now).

 

You're running a hotter cam and with all that other work done to the motor the max you saw was 168 g/s. I hope your MAF is providing inaccurate data. Swap in the spare MAF from your parts truck, rerun the exercise and compare the data.

 

Pull the K&N filter off and retest. Bet that changes the result.

 

You're probably dreaming of a larger one & misinterpreted the smoke and mirrors writing while reading. Actually you got it correct the first time, there is not a 3rd larger sensor. D2 & P38 4.6 MAFs are the same. My take is the Brits never saw the 4.6 in the D2.

......

 

Well, the MAF from the parts truck kinda... Git hit by a lawn mower. Whoops. My exhaust is a huge point if restriction right now, the y-pipe is suuuper cobbled together and has a couple crush bends in it that are causing a lot if restriction. It could be accurate. I have been meaning to replace it, but the truck has needed other things.

I will test again without the k&n as dgi recommends. I'll see if I can pick up some electrical contact cleaner to spray in it too.

 

For comparison sake and the fun of it I'll get some data tomorrow. Stock 4.6 motor with what I can only imagine is the factory MAF. 124k on the motor.

 

Uh, What was your lawn mower doing under the hood?! Haha
Trying to free up those damn irreversible clamps?!

 

So I finally got a reply from Bosch today. They state that the original maf in our truck reads from 3g/s to 177g/s. I have asked if they could send me info on a maf that would read higher g/s levels for the truck. It also sounds like the 240 something reading I had was not the actually reading from the maf but the truck defaulting to a higher rating since it thought it was getting more air than the maf could properly read. Also that was what tornado systems was talking about on the link I put in before. That the Thor engine needs a better maf or maf upgrade to properly take advantage of any extra air the truck receives.

 

Very interesting. I would assume that those limits were for the smaller 4.0 MAF housing and that the larger housing on the 4.6 trucks and the larger yet housings on the Rangies was specifically because of this so the MAF would be able to send the same voltage for a larger amount of air to the ECU.

I remember reading something, probably a couple of years ago, about someone who had retrofitted a different MAF sensor. I cant remember very well, perhaps a Volvo or Volkswagon part? I'm not sure. I'll do some looking and see if I can find it anywhere.