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Hi Flow exhaust+Air Filter O2 issues?

lowflyingbird

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Joined
January 21, 2002
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City, State
NewYork
Year, Model & Trim Level
98 EX 5.0p
Hi,
I have a 98 5.0 Explorer, changed from 4wd to 2wd. Installed a higher flow exhaust. I used the dual flange off the cat converter (muffler side) welded 2.5 pipe custom Y-pipe to create single inlet into muffler. Muffler is a 2.5 Dynomax stainless UltraFlo or MaxFlo which ever its called, Its the one designed like a Borla. Going out the back through a 2.5 over axle pipe. I also changed the intake filter to a conical K&N type with a 3.5 pipe inlet adapter, keeping it all together IN the stock airbox. One other thing is the egr pipe running from header to EGR cracked from age. I eliminated it caping the egr provision on both header and egr. I'm getting no trouble codes from EGR.HERE IS MY PROBLEM, I am getting a code 133. This is for upstream driver side O2. I've changed it twice and also changed the pass. side. I can not get rid of the code. I do clear the computer and it comes back the next day. And judging by performance something is wrong, It was the same even before eliminating the EGR pipe. I do plan on changing my muffler to a Dynomax turbo in 2.25 or 2.5, since this UltraFlo I currently have resonates so much sound even at 1800 rpm i could wake a dead deaf man !!
Any recomendations/ experiences?

Another issue, I plan on putting a set of 1.7 rockers on this thing, I think that keeping the cam profile might be a good idea (torque), but some more lift couldnt hurt ?

Please reply
Thanks
Keith
 



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Ok , from my experience, first you should repair the egr tube, but we'll deal later with that
The rocker arm idea sounds cool, but unless you change your computer you won't rev above 5500 rpm's
Assuming you do that,first new valvesprings are in order. I beleive the stock valve covers won't clear the roller rockers, meaning you need taller ones, with the oil fill in correct end, then you will need a 1" phenolic spacer between the upper and lower intake manifold plennums to clear the taller valve covers
Then you lenghten the egr tube 1" to make up for higher upper plennum
I myself have done this and learned from experience
My COBRA valve covers didn't clear my roller rockers and they are taller than stock. A 5/16 inch thick gasket bought me just the needed clearance, I used a chunk from old egr tube and had it tig welded in
as for the code 133 is there a chance the 2 o2 sensor plugs got crossed?
did you say the egr tube was cracked before and you had code before?
I am not absolutely sure, but I think the egr circuit is pretty hard to fool
 






Hi,
Thanks for the reply, good to hear from someone who has already played with this. I figured it was just a matter of time and I would most likely have EGR issues with what I had done. I can do as you stated to a tube. I figured that the covers would definitly not clear the rockers. I was going to pick up a set of 90's Mustang aluminum ones. I have played with a few 5.0 motors before with cams 1.7 rockers,KB blower etc. But even with the same motor ,applications and computer changes over the years, make a mod for one not good for another.Surprised to hear that a full 1" is needed though.I do have one question, you mentioned that your "COBRA" covers did not clear, I know what they look like, similiar to Explorer covers. I thought that Ford put the 1.7 Crane energizer aluminum roller rockers on those?

As for the codes, The #1 driver side O2 upstreem code 133 is the only O2 that does not plug in above the transmission. I also changed the pass side #1 upsteem due to conflickting manuals. The EGR tube was cracked prior.

BUT COME TO THINK OF IT, On the PASS side when I opened the floor panel I did note that the #1 O2 was not pluged into the foward most plug on the harness, if thats correct or not I do not know. But the O2's were all origional.

Do you know if the EGR pipe is dealer only ?
Please reply
and Thankyou again for the help
Keith
 






Yes, I did have to get it from a dealer, was on backorder in june, but I complained and they "found" me one the next day. I was told it was redesigned for more flex.
In my case, I have crane 1.6 rockers, and they hit the baffle plate inside, on the valve end of arm, so it wasn't a cam lift issue, but come to think of it those cobra roller rockers are kind of low profile on the valve end aren't they?
I mean mine was barely tapping
 






You are going to hate me for suggesting, but I think the upstream sensor plugs into the forward plug. try switching them around ( yes this sucks), disconnect your battery before you start to clear code.
If I'm wrong I know you'll hate me :(
those things are a big PITA to plug in, unless you access thruogh the floor hole.
 






I should have tryed it when I had it all apart. Removing the console and all was just such a stupid Ford move. I guess the accountants wouldnt have gotten their bonuses if the added a few more inches of wire to the harness making it easy to change. On that note, Did you know that the driver side and pass side O2 (upsteam)are the same, the only difference is the wire legnth. The driver side is shorter but more expensive the pass wire is longer and about $15. cheaper. I found this out when looking up replacement parts that the universal O2 fits both sides. Making the only difference the wire legnth. 3" wire less ? = $15.more AAAUUUHHH!!! who do I smack?
 






lowflyingbird said:
I should have tryed it when I had it all apart. Removing the console and all was just such a stupid Ford move. I guess the accountants wouldnt have gotten their bonuses if the added a few more inches of wire to the harness making it easy to change. On that note, Did you know that the driver side and pass side O2 (upsteam)are the same, the only difference is the wire legnth. The driver side is shorter but more expensive the pass wire is longer and about $15. cheaper. I found this out when looking up replacement parts that the universal O2 fits both sides. Making the only difference the wire legnth. 3" wire less ? = $15.more AAAUUUHHH!!! who do I smack?
Instead of hitting him, let's hang him upside down and take what falls from his pockets, then smack him, and tie him up with 3 inch pieces of wire twisted on every spot you could get them around.

Well let's just say i was a bit put off also
 


















Hi,
I'm going to get all the parts and I'm going to install ,the rockers/covers/intake spacer. And cut out the flex area from my egr tube ,then make the extension using a peice of green silicone egr hose. If that does not do it ,I'll have to go to Ford and buy a new one and extend it like you had done. I'm also replacing the stainless Dynomax Ultraflo muffler with a Dynomax super turbo.
Thankyou
Keith
 






For an experiment, before you tear into it run it up to operating temperature and feel how hot the upper plennum is, then again after the phenolic spacer is installed. You will notice a dramatic difference. I can rest my weight on one hand on my upper intake when fully warmed, I think this helps the intake air charge quite a bit
 






Hi,
I can believe you on that point. On a previous Ford 4.0 OHV I had ,I tried running one of those cone OPEN air filters with no box. It sucked up nothing but hot off engine air. It was a pig off the line and lost power. In my Explorer 5.0 I do have a cone K&N type filter, BUT it is inside the air box. So the spacer is going on.
 






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