What gearing does the truck have? The E4OD seems to be the worst for fuel milage must be something to do with how it's programmed, but what milage are you getting now?

Honestly shorties bolted to the stock Y pipe probably won't help you at all, a cam change to the '94 spec roller cam and longtubes would but that may be more work than you're willing to do. If you truck is one of those with 3.08 or 2.73 gears swapping in 3.55 to 3.73 gears would improve overall milage.

 

Well heres a question that may help you... On our trucks the cat. is located on the I pipe where the Y pipe gos into the cat and back in a single I pipe so techanically you could keep the cat. in the same location as stock if you ran longtubes with a Y pipe... Here in tennessee if you have emissions all they care is if you pass the sniffer where you will with longtubes as long as you have a cat.

 

or you can just find a loophole in emissions testing and get your truck exempt and run long tubes with no cat or smog pump. your local mechanic shop will probably be able to tell you what mileage you need to drive under per year to be emissions exempt (in pa it's 5000). then you just get a new gauge cluster and swap the new one in right after inspection and swap the original one in right before inspection.

 

No.. the collector on longtubes comes much further back and leaves no room for a cat between it and the trans crossmember, and besides that this also means the Y collector has to go behind the transmission so there is simply no way to put a cat in the stock location with longtubes. Here are a couple pics to show what I mean...


5.8 Exhaust 105.jpg on Flickr - Photo Sharing!
New Exhaust 100.jpg on Flickr - Photo Sharing!
50Exhaust 006 on Flickr - Photo Sharing!

 

Been out all afternoon. First, thanks everybody for your answers. Will try to answer some of them in order here.
1st up is C M Colfax. I read the part about they could only be replaced if they failed. Seem to remember something about the shop had to fill out a certificate on that. What if you replace it yourself? I don't know. If as you say, the stores don't require an old one exchanged, who knows. You make sense there. Have never actually shopped for one. Also, if anybody can answer a related question, there was something in there that dual ( I have 2 in line ) could be replaced with a single IF it did the job of both. That also sounds interesting & would give me some room. How would I know if it did? Do they say " replaces both " or something?

Next is Conanski ( twice ), 1st reply, don't know the gearing, haven't checked it yet. Need to get the numbers off the door tag & list them here on for deciphering. Don't know the milage yet. Haven't been driving it much yet. Just filled both tanks ( almost $80.00 ) tonight & wrote down mileage. Don't think I have any tank to tank leakage ( cross flow or whatever I should call it ), but I have read about it happening to enough other people here that I want to re-fill both tanks again & write the milage down then in order to get an accurate reading.
2nd Don't want to get into internals on the engine till I have to. Was planning on replacing the entire system IF I do this. What's on there now is on it's last legs. Most of my driving will be local, not much highway. Wouldn't going to a lower gear hurt the milage? Always thought that higher RPMs meant more fuel used = less mileage? Am by no means an expert, this is just what I always thought. That's why they started putting overdrive trannys in I thought was to lower the RPMs so you would use less fuel? I'm not trying to say anybody's wrong, I'm a & don't know Jack. I'm just going from what I always thought. Again, thanks everybody.

FTE Rocks & RULES!!

 

Conanski, just looked at your pictures, couple questions please. 1) Did you have to lengthen your ERG tube to fit? 2) If you did, how? 3) One more, what about the wiring for the O2 sensor, did it reach?

 

Hope some of the stuff I write is helpful...

I have bought universal fit replacement cats from parts stores and not had to provide a core, clamped them in place and drove on...

As for one cat replacing multiple, from what I have read in parts catalogs, most of the new ones state that they can replace multiples in engines up to 5.9L and GVW's of up to 5500lbs.

(Or something like that.... check Summit or Jeg's or JCWhitney...)

Another good source of info is here:

Bear River Converters - Wholesale distributors of catalytic converters

I am pretty sure he is a FTE member too.

I am following this closely 'cause it is on the list of projects for my truck. There are a couple more little things I NEED to do so it can take over DD duties while I catch up on some much needed PM/upgrades on my Grand.

Then I'll get in to the WANTS for the truck...

-cmc-

 

Total fuel consumption depends upon a lot of fators, vehicle weight and aerodynamics, overall gearing, engine size, and driving style. So there is no one size fits all every vehicle will be different and best milage comes from a balance of factors. You are right that in general higher engine rpms increases fuel consumption but so does increased engine load and this is what happens with really high(numerically low) gearing. As a result changing to slightly lower gearing can totally offset the potential increase in fuel consumption resulting from slightly higher engine rpms. IMO Ford screwed up by putting these ultra high gear ratios in these trucks, 3.55 seems to be the happy medium for most of the chassis and engine combos and higher gears just hurts milage and the trucks ability to do work efficiently in the real world.

 

No, and the EGR tube pictured is actually a 5.0 tube but it's on a 5.8 motor and it's not attached to the header in the stock location, that's just where it reached comfortably.

Yes, the O2 wiring harness is wrapped with some other things and there is quite a bit of extra wire in it that can be freed up by removing the tape and wire loom around it and seperating it from the other wires. It connects to the main engine bay harness up behind the battery.. on my truck at least, and the portion between that point and the end that connects to the sensor is about 5 feet long.

 

For the 96 i instaled Hedman shortys with the magnaflow cat kit (two cats) i noticed a "Mid to upper" torque gain, you realy feal it on the hwy !! Mileage didint change mutch still around 15/16

 

Thanks again everybody for your additional info. Friend of mine says that since I don't have to pass the smog inspection, they don't even bother with a visual check. Still think I'd like to put one back on in case they ever decide to look for something else.

1) C.M. Colfax, again thanks for the added info. Was curious about the 1 for 2 deal. Thanks for explaining that.

2) Conanski, same to you. Thanks for the additional info., didn't even consider weight / strain on engine in regards to fuel milage. You say you suggest 3.55 for gears, will remember that. If I ever remember to get the numbers off the door, I'll find out what gears I have now. I would suppose that since I have a 302m ( 5.0 ) that my tube should reach about the same place & if the O2 sensor wires can be separated to plug in there, I should be good. Will find out what mileage I'm getting this time & compare after ( IF ) I do headers. The whole system is about shot, just passed inspection. The guy at the shop even said, no way it'll pass next time. Would like to do headers at the same time as I'm going to have everything else off. Just curious, what brand does everybody recommend. Have always heard Hooker was good ( looked at them on the computer, see they're part of Holley. Never knew that. Holley, I think carb., not headers. ).

 

Jason, thanks for the info. Have pretty much decided after all I've read here, that IF I do this, I'll go with long tubes. Especially since seeing Conanski's pictures & what I've read about " stock location " meaning after the Y pipe & in front of the muffler.

 

Are these the long tube header you guys mean, at the top of the list?

http://www.hedman.com/products/?id=3538&iset=9187&rsku=

 

That's one brand & a general idea of what I meant yes. " Shorty ' headers are the same size & shape as stock manifolds & your Y pipe bolts up the same as if they were stock manifolds. No cutting / welding / fabrication required. If this worked, here's a sample picture of "Shorty " headers.

http://www.holley.com/data/products/...rge6128HKR.jpg

 

Geez those shorty header are quite ugly haha