i guess a couple of questions.if pcm stock just does not want to shift around 4200 rpm,just acts like timing is retarding does not want to keep reving and i have to let off to shift,will it act the same way after i install edge level 2 program?i had dealer tell me the knock in my engine was a def cam timing sensor.they replaced and knock is gone but after truck was running rich turning tailpipe black and lost 2 or more miles to gallon on milage.they said cam timing sensor had nothing to do with rich condition but i say bunk.they reprogramed pcm and was a little better.do i need to go back stock and have them check again???sorry i forgot this is a 2005 screw 5.4 2wd auto.

 

Black exhuast pipes are not indicative of running rich on late model vehicles.
You will have to look far and wide to find a non blackened exhaust as the unleaded fuels will not leave that chalky white/gray exhaust that we came to know back in the 60's and 70's..

 

then the question i have is why are there as many clean new body style f150's tailpipes as there are black ones?also mine was clean till they replaced my cam timing sensor and i lost 2 mpg and they said that had nothing to do with replacing sensor.doesn't cam timing sensor have something to do with timing?thanks if anybody can enlighten me on this.

 

Hi RF,

Yes, the cam timing on the 2004 & up 5.4 3V F-150's *can* affect timing, as well as cylinder filling. With a defective cam position sensor, it could very well have been running lean and also with to much timing - which is what I suspect, as you clearly tell us that it was knocking.

Now that condition has been corrected by the new sensor - well, timing is now back to where it should be, and cylinder filling as well, so the A/F ratios should be much more accurate.

It is entirely possible to lose 2 mpg from having a defective cam position sensor replaced - that tells you, along with the obvious knocking it was doing before, that the engine was NOT running right.

Also, forget the inside color of the tailpipe, you CANNOT use that to say that it's running rich or lean - the ONLY way you can determine that is with actual wideband Air/Fuel ratio testing - period. It's not an old carbureted engine, it's a new modern EFI motor with cats on it, and the tailpipes generally look blacker than they did on older engines across the board. Additionally, there are a good number of trucks out there that are running lean, especially in the 2004 & up F-150's, due to things like contaminated upstream O2 sensors (like we found on Marc's truck right from the factory) due to anti-seize compound getting on the end of the sensor, and other causes.

In short, it sounds like the truck is running a lot better, and closer to what it SHOULD be doing - I would forget worrying about the 2 mpg you lost, as it obviously was not sustainable, and was due only to the cam position sensor being bad and thus delivering too much timing as well as a cylinder filling issue that likely resulted in a lean condition.

the only thing that is going to tell you what that engine is doing is proper datalogging, to include chassis dyno testing of the A/F ratios, etc. You cannot guess at any of that by tailpipe color, etc., the only way to diagnose is with proper data - that is the nature of today's vehicles, especially when it comes to fuel mileage, A/F ratios, timing, etc., as none of those things can be diagnosed by look or feel - that's guessing these days, and it's hard to accept for a lot of us who grew up on pre-EFI vehicles especially - I know it was for me years ago - but being a professional tuner & modifier of these vehicles, I can tell you that you need data to diagnose - you can't guess at it by tailpipe color or the fact that you lost 2 mpg after having the vehicle repaired so that the engine is now running correctly and no longer knocking.

I hope that brief info helps,