This may not be the right forum but it seems to have the most knowledgeable people about this topic in it.

I installed a AF1 about a month and a half ago, had problems with a CEL got it to clear up after about 3 weeks, then it came back, cleaned the MAF because i noticed my filter lost A LOT of color and figured that the oil ended up on my MAF, so i cleaned it and it was great till the last couple days...
i've since cleaned it again (today) and it still is throwing lean codes now.. my question is that in the last few days the temperature here has dropped like 30 degrees, and its my understanding that the MAF works by sensing how long it takes to make it a certain temperature, would the quick change in temperature effect it and make it throw the CEL again? i cant remember but i thought i read somewhere that cold temperature effects it.

 

The air temp is a seperate sensor in the tube.
The air meter is a hot wire bridge that is heated by a regulated voltage supply.
The airflow cools one leg of the bridge changing its resistance and therefore the voltage signal to the PCM as a calibrated way to determine airflow.
Your air intake system has upset the airflow calibration of the air meter.
Add the filter oil migration off the filter with the airflow and the deposits it makes on the hot wire part of the bridge and you end up with the problems you now have.

 

Bluegrass, solution?

I sense an implication to return to the stock intake?

Joey

 

If i read this correctly, youre saying it could be that the oil build up on my MAF from my new filter is causing the problem because its not being cooled like it should be if it were clean? what effect is this going to have on driving.. im kinda worried about as im going out of town TOMORROW!! on about a 400 mile trip hauling 2 big quads..

 

All i'm saying is if you just changed the air intake plumbing and this brought with it your problems; I just attempted to explain what most of the change cause and effect can be.
The lean code should be suggesting that the air meter "sees" less air per the throttle opening than what the PCM 'knows' should be the case hence the lean code.
There's not much to it but it sure has a big influence on the end results.
Looking a little closer, the air sample the meter does is only a low percentage of the total airflow. This could have been altered by flow dynamic inside the new piping assembly.

I would at least try to rotate the air meter in an attempt possibly get the air meter to flow more nearly the correct amount of air but then you still don't know how correct it is even if the CEL and code is satisfied.
This is why custom tuning is done for mods.
This is also why the one size fits all dosn't work at times.
What you do about this is your decision.

 

Hi Rawzon,

Sorry to hear you are having a problem!

However, as you probably know because you have been here a good while now, Tech Support is not done here. Also, try using the SEARCH feature, as this is something that has been gone over literally countless times, thus all pertinent info is available via using the SEARCH feature here.

The smart thing to do would be to actually datalog the vehicle - as I'm sure you know from seeing many of my posts, the 2004 & up F-150 (and a number of 2001-2003's, too) set lean and rich codes LONG before the engine actually goes rich or lean, because the code reporting threshold is tighter than the adaptive range of the PCM - and that we have also seen engines running as lean as 19:1 never throw a lean code!

What needs to be done to properly diagnose this is to have the vehicle datalogged/tested to see if it's actually running lean, and if so, by precisely how much so that it can be corrected in tuning. And if you are concerned about needing to take a trip right now, simply put the stock intake kit back on for your trip, and then deal with this properly when you get back - it only takes 10-15 minutes to swap out the intake.

By the way - in the 2004 & up 5.4 3V F-150, the IAT sensor is an integral part of a far smaller MAF sensor design that uses no traditional meter housing, and cannot simply be pulled out. Nor can anyone just "rotate" an air meter on that truck, as there is no traditional air meter housing that can be rotated - nor would it be wise to rotate that on an older vehicle that does have that kind of design in an attempt to get a CEL to go away.

The proper way to diagnose this is to first, know what is actually happening - what are the fuel trims at numerous points in closed loop, and what are the Air/Fuel ratios in Open Loop - then you will actually know if the engine is running rich or lean. You cannot always depend on a dash light to tell you that accurately. See, "Check Engine" or "Service Engine Soon" lights are designed to come on only when the vehicle exceeds it's allowable emissions level by more than 50% for a certain amount of time (drive cycles) - it's not there to "protect" you against a lean or rich condition, so just keep that in mind.

The hot tip would be to have a good custom tune done so you can get the most out of the intake kit if your vehicle is actually running rich or lean - or if you have a tune, have it adjusted by providing your tuner with proper datalogging info. Most likely, if it is actually running lean, it was also running lean before that intake kit ever went on, it just didn't throw an MIL - that is a characteristic we have seen in many of the 5.4 3V F-150's by the way, especially in 2004's.

If you do not want to do the proper datalogging so that custom tuning can be done, then contact the manufacturer directly to have them send you one of their 3" (internal) tubes once you get back from your trip.

Good luck!

 

got back from my trip last night (ended up being 1200 miles).. the cel came on and i just left it on.. it actually went off during one cycle by itself which hadnt happend before but it came back on 2 cycles later..

And yes i know ALL about the search feature, i swear if theres a post i havent read about CEL's by now i'd be surprised and i couldnt find much about my temperature question which is what my question originally was.

I believe now that the filter is being the culprit here because its lost a lot of color, which im guessing is the oil and every time the cel issue gets bad, i've cleaned the maf and its helped. so im thinking that once the oil from the filter has stopped dirtying up the maf, the pcm will be able to do its adjusting without being screwed up by the dirty maf.

also im waiting for my xcal2 and i plan on datalogging it

 

Hi Rawzon,

Thanks for your post - and I'm glad to hear you made it back from your trip OK, as there's a lot of snowing going on right now over large parts of the country!

As you probably know, due to how many people are here, I can't remember who has done what or ordered what, so thanks for bringing me up to speed on the fact that you are waiting on your XCal 2 (and that you already know all too well about the SEARCH feature's value!!)

When we do your tuning, there are adjustments we make for the 3.25" & the older original 3.5" AF1 tubes that will help with the A/F's in those vehicles that run lean from the factory (those are the ones that have the CEL issues with some intakes), but as you very correctly pointed out, you will still want to do the datalogging so we can dial that in for you - and that is all part of our custom tuning service, those adjustments dictated by the data you send us are included free as well.

If you'd like to give us a call and just leave your correct name and phone number, we'll be happy to let you know about when to expect your XCal 21, as we are getting a TON of them knocked out right now, especially over the Thanksgiving weekend. Though we are now closed for Thanksgiving until Monday morning, we do have voicemail on 24 hours, so if you;d like to give us a quick cal with your real name & a phone number to call you back at, we'll be more than happy to see exactly where yours is at and when you can expect it, if that will help you.

Oh, one tip on the air filter - the blue colored dyes *always* tend to fade away more quickly, so unless you don't mind cleaning the MAF sensor frequently (and that is something we prefer not to see done more than once a year), I would suggest using the red-colored dye oil when you clean & re-oil your air filter element. It lasts FAR longer, and you get much less migrating oil. there is just something in the pigment of those blue-colored oil dyes that causes it to fade much quicker, we have seen over the past couple of years.

For example, on my Lightning, I of course use the AF1 intake kit, and use to use the blue colored oil dye when I cleaned & re-oiled the filter - however, I did NOT see any increase in the amount of oil migrating onto the MAF sensor's hot wires - what's happening is that the blue colored dye simply *evaporates* far quicker, so it's really not something where your MAF is getting dirty that much quicker. I do still feel that all MAF sensors should be cleaned with electrical contact cleaner that does NOT attack plastic one a year - then store the MAF sensor assembly so it will dry for a good while, as the contact cleaner drops a bit & finally completely evaporates.

Just FYI, I hope that info helps a bit more!