I posted this in FTE forums and no responses.... So hopefully someone here would help I have the 3.0 flex just to clarify. But the other day I did the maf mod to it and now have a C.E.L. indicator on. The codes I pulled are PO171,PO174. So that means that banks 1,2 are running lean..... I unhooked the negative cable for an hour then let truck idle for 20 mins, it runs fine but after I drive for ten minutes or so that blasted light comes back on , and Ive done this several times. What gives the only time I pulled a PO102 code was when I unhooked the M.A.F ... And heck I think it ran better than with it on "no pings". Whats making my truck run lean? If its the M.A.F is there any thing else I can do to it to fix this crap...
Oh and by the way its the maf that is complete cast alum.

Thanks,

Pj

 

I think one thing to note is when your computer switches from closed loop to open loop it sets off the check engine light. Someone who's done that mod and has experience will probably answer soon.

 

I have no clue as to what that means .... Enlighten me "this is the first newer model truck Ive ever owned"


Thanks,
Pj

 

Okay so obviously your truck has a computer in it. When you first turn on your truck, it's using data thats preset in it to run your truck. Such as air/fuel mixtures and whatnot. Just stuff that the sensors sitting in your truck could be measuring but arent. Once you reach a speed of about 60 miles per hour for a sustained period on a road your truck computer then has all teh sensors start giving it information. It becomes open loop, meaning its receiving data. So that 10 minute wait before your CEL turns on means most likely the sensor kicks in once you have driven long enough and notices a problem.

Oh, and when i say closed loop the sensors are off, i dont mean every single sensors. Just a good amount of them.

If you lived in a small town like I do, its actually pretty bad because rarely does my truck reach open loop. There's no faster than 55 in my town and the roads aren't that long, so most of my drives are a few miles at 35 mph.

Aaron

 

Sorry but that ^^^ is not how it works.

 

Thanks that clears things up......


PJ

 

Dude... You are waaaaaaaay off. Closed loop is operating loop. Closed loop is acheived when the vehicle reaches operating temp. The "sensors" are never "off", you have no idea what you are talking about... WAY over your head... Dont mislead people like this. If you arent sure what you are talking about, just dont say anything...

 

No it really doesnt... Make sure you have everything reinstalled the way you took it off. Make sure all of you intake connections are tight(intake tube) and you MAF connector is clean and making good connection. After that, you may want to take the MAF back off and be sure you didnt damage something or there isnt any debris in the sampling tube.

 

When you do the MAF mod, you are changing the relationship between the inake air flowrate and the voltage that is sent to the PCM to represent that flow rate. In other words, you are changing the mixture because the MAF is now incorrectly reporting the air flow rate to the PCM.

In your case, you have changed it enough to exceed the limits of the OBDII diagnostics - that is why the CEL is on. IMO, the only way you will get rid of the CEL is to undo the MAF mod. That would require a replacement MAF.

 

^^^^ That too!!!

 

Okay so that mod is a shot in the dark kinda thing.... Okay I am glad that I bought one off of ebay just in case...

 

Ok I will refrain from doing that mod because I have the metal MAF as well and dont want to be spending $50+ for a new one.