Well I'm in Miississippi but we are runnin that 10% ethanol down here too...I noticed a difference with that crap when I was in Florida back in January of this year... even in a rental van...it sucked

 

I'm getting 16.7mpg in the 5.4 '08. That's running 0.1 eth.

 

I really dont believe that aftermarket air kits have any benefit whatsoever. I have tried them myself and have noticed no real power improvement, or mileage improvement. What I did get was more dirt in the intake tube.

 

Your trucks not tuned to run without cats. Mods help very little without. Your in desperate need of a tune.

Add some high flow cats to go with that muffler / then tune and I'll guarantee you'll see a difference in MPG's if you drive her civilized like.

 

have you tried checking your injectors to see if one is shot and is going spray happy?

 

I appreciate that JBREW. I have read a lot of your posts on here and really respect your opinions (don't get jealous guys...yall's posts help 2). I was hoping that you chimed in on this one. Any suggestions as to where I should shop for those cats...I usually shop at autopartsgiant.com, autopartswarehouse.xom, and mechanics-warehouse.com.

I was wondering If I was messing up by gettint those cats cut off...

 

Not to speak of the fact that removing the cats is illegal.

 

I only scanned the above post but have you changed your fuel filter? Its a quick and easy event that can help if its clogged.

 

The Tuner from the catalog - http://www.troyerperformance.com/cgi...catalogno=9400

The cats - http://www.troyerperformance.com/cgi...c%20Converters

How the 5four sounds w/22x4 race series Magnaflow muffler, Magnaflow HF cats and LT headers -

http://picasaweb.google.com/jbrew393...40433327124514

BTW - That wasn't tuned, sounds better when tuned.

 

So JBREW am I supposed to be putting all four cats back or just the two up front

 

Omilty, I have an '00 4x2 XLT @ 100,000mi myself and only get 12mpg city and about 18hwy. I am working on getting it better but nothing so far. Did you do the COP's and plugs yourself? Thats my next step I am thinkin.

 

I doubt you will do better than that on the goat **** gas in the Chicago burbs.

 

Oh yeah...I did them all myself except for the two back ones on the drivers side...but I gapped all of them myself

 

Nah, just two that are compatible with your OEM's ( Front/Rears, whatevers easier.). Used cats on these trucks are selling @ the same price your going to pay for a new set of Magnaflow HF's . I take that back, Salvage prices went higher since, so you can make money trading up to HF's - If you do the work yourself.

If you still have your stockers laying around - Weld a flange on each side and reinstall. That would be the way to go (with a stock tune). In fact, the OEM rears alone in this system (without pre-cats) isn't really going to flow much different than one with after market HF's.

Personally, I would throw a couple cats on your truck/ You won't need a full Cat Back system at this point. - Keep it all 2.5 into a good SISO offset muffler (Magnaflow and Borla mufflers are top notch ( Well Borla anyway ) - Borla also makes Roush Mufflers. Borla has topped the lists in performance in the past ( OEM & The upside from that), you can't beat the construction.