Dismiss Notice



Register Today It's free! This box and some ads will disappear once registered!

Help my 4.0 breathe

Discussion in 'Modified 1991-1994 Explorers' started by SuperKirby, June 9, 2015.

^^Searches ExplorerForum.com^^





  1. SuperKirby

    SuperKirby Active Member

    Joined:
    June 23, 2012
    Messages:
    205
    Likes Received:
    0
    Trophy Points:
    0
    City, State:
    Central MN
    Year, Model & Trim Level:
    1993 Explorer XLT
    I've noticed the exhaust has started to smell pretty "metallic" which I understand to be a sign the cats are on the way out. Add to that the other day the last heat shield fell off the cats and the hanger on the cats broke, I probably should think about changing them. There's no vehicle inspections here, so I could do without the cats altogether. I'm trying to figure out if I'm better of to get rid of the cats or go with something like the Magnaflow high flow? If I do the Magnaflow does that have to be welded up or can you buy a high flow cat that bolts up to the y pipe?

    As for the intake, I've looked through some old posts, some recommend just getting the MAF adapter and cone filter, others recommend new stuff from the throttle body to the filter. Without doing valves, cam, etc, will I gain enough to justify a whole new intake? Or would it be money better spent to just do the adapter/filter?
     
  2. Support EF

    Join the Elite Explorers for $20

    Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see practically no ads, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create more private Conversations, and more. Join Today. Your support is greatly appreciated.



  3. Anime

    Anime EF YEAH!! Elite Explorer

    Joined:
    November 6, 2000
    Messages:
    5,445
    Media:
    9
    Albums:
    1
    Likes Received:
    24
    Trophy Points:
    48
    Year, Model & Trim Level:
    2018 EX Sport Concept
    You can't just "get rid of" the catalytic converter. It doesn't matter that there are no formal inspections for it. It's still a federal crime to remove a catalytic converter from a vehicle, and not replace it. The clouds of dark exhaust smoke from a vehicle without a converter are pretty noticable, not to mention the foul exhaust stench. Either of those are more than enough for a law enforcement officer to pull you over and inspect the vehicle. You are looking at a $25,000 fine, and/or 5 years in prison, all to save $100-200.

    If THAT isn't enough, people can DIE or get very, very sick from the carbon monoxide that an un-converted exhaust puts out. People have died from inhaling the fumes from rusted pipes ahead of the converter, and that was just small holes. Driving a vehicle with no converter is basically just being a jerk and not caring about your own health, or the health of others. People have the right to breathe air that isn't going to get them sick or kill them just because someone is too cheap to buy a converter or believes the false information that removing the converter from a vehicle will let it make more power or somehow run better. Both of those are untrue in the extreme. Modern vehicles are designed to run best and most efficiently with working emissions systems.

    As for the converter, any of the replacements from Walker, Magnaflow, or other major exhaust companies should be fine. I doubt that the Magnaflow unit flows more than the other OE replacements, just aftermarket units sometimes flow more than the older factory units so they tout theirs as "high flow". The Walker kit supposedly is a bolt-on, though they now offer the converter hanger bracket as a part with a U-clamp, so my guess would be you have to either use that or weld on the hanger. The Magnaflow kit should be similar, bolt-on except for the hanger on the converter.

    If you don't want to spend the $200-300 on a 2-converter OE-type bolt-on unit, you can get a single 3-way high-flow converter for well under $100, and have a pipe made up so it fits in place of the factory unit. I would suggest using a 2.5 inch converter and 2.5 inch pipe, which is the size of the factory converter. The pipe can be ovalized on the Y-pipe end and the factory flange either cut off and re-used, or some exhaust shops may have or can order replacement flanges. The other end is easy enough to just weld on a standard 2-hole flange with a little of the pipe sticking out the end, and use the same gasket as the factory, letting you use the same off-the shelf replacement parts as if it were a factory converter, if the positioning is still the same.

    You can buy a cheap MAF adapter and cone filter, but I suggest going for the KKM kit, that has a machined aluminum adapter and S&B filter. The S&B flows more than the cheapo filters, and the high quality of the kit makes it worth it. I think it's also worth supporting a vendor that still makes products for the 1st gen Explorer.

    You don't gain much if anything replacing the intake tube, but some have done it since the factory plastic tube eventually gets cracks and holes in it, and is $100+ to replace.

    Overall, even on a bone stock Explorer, just replacing the factory air box with the KKM intake kit and replacing the muffler/exhaust with a cat-back like the Dynomax Super Turbo kit will be the biggest bang for the buck in terms of performance.

    A new converter can also help, especially if the factory converter is in poor shape. Even a budget 3-way converter put in it's place should flow more and work better, just based on age and the advances in manufacturing and tech over the past 20+ years.
     
  4. RangerX

    RangerX Elite Ranger Staff Member Moderator Elite Explorer

    Joined:
    July 14, 1999
    Messages:
    9,743
    Likes Received:
    220
    Trophy Points:
    83
    City, State:
    Omao, Kauai
    Year, Model & Trim Level:
    '93 Ranger XLT 4X4
    Also, any further mention of running without cats in this thread will cause the thread to be deleted, FYI.
    Because it's a federal law, the forum won't tolerate discussion of violating said law.
     
  5. SuperKirby

    SuperKirby Active Member

    Joined:
    June 23, 2012
    Messages:
    205
    Likes Received:
    0
    Trophy Points:
    0
    City, State:
    Central MN
    Year, Model & Trim Level:
    1993 Explorer XLT
    First, I'm sorry for crossing any lines or anything along those lines. I'm certainly not trying to promote any illegal activities, law breaking, etc. Merely questioning things I've read and been told.

    That said, I'll look into having a shop weld up some sort of flange setup that would allow use of a $100 cat now and in future changes if required, rather than have to drop 2-300, especially as much as things rust around here.

    I had looked at the kkm kit, looks like maybe that's the route I'll go. I already have the Dynomax kit on it, put on last summer. I just need to figure out what to do from the Y pipe to the kit. I really don't want to spend $300 on stock cats so perhaps the magnaflow would be the way to go.
    Probably a dumb question but can you bolt a cat on with muffler clamps?
     
  6. Anime

    Anime EF YEAH!! Elite Explorer

    Joined:
    November 6, 2000
    Messages:
    5,445
    Media:
    9
    Albums:
    1
    Likes Received:
    24
    Trophy Points:
    48
    Year, Model & Trim Level:
    2018 EX Sport Concept
    You can bolt a catalytic converter on with u-clamps or band clamps, but it's not a good idea. You really want the converter to be airtight on either end, and where the pipe on either end meets the Y-pipe and the muffler. Given the deadly nature of what could happen if those clamps ever loosened, it is not worth the risk. Better to spend a little more money and have it done right, welded up airtight. Converters are (usually) made of stainless steel, so they usually last hundreds of thousands of miles and beyond. Ford cheaps out on exhaust and uses mild steel that rusts easier, and the cats last a good while, but the aftermarket one you get will probably be the last one you'll ever need to buy for the vehicle, unless some sort of engine issue causes the converter to go bad.

    It should be VERY easy for an exhaust shop to take a universal 2.5" 3-way converter, and weld 2.5" exhaust tubing to either end, expand and crush the Y-pipe end to match the factory flange, weld the Y-pipe flange on, then weld the 2-hole flange on the muffler end, leaving a little sticking out so the stock-type gasket will go on, and the Dynomax exhaust will bolt up to it like it's still the factory converter there. They will probably have to do a little tube bending here and there to match the angle of the factory converter to get it to fit right.

    It should be a fairly easy job for an experienced muffler/exhaust shop, especially since they'll have the original converter assembly to work from.

    My suggestion would be to call or visit your local exhaust/muffler shops and ask what catalytic converters they sell and what a 2.5" would cost and get an estimate on what it'd cost out the door to replace the converter on your Explorer. It may be quite a bit less than you are expecting. You may even find a shop that sells Magnaflow and that has 2.5" converters in stock for you to look at.


    Here's a thread on replacing the cats in first gens with a universal one:

    http://www.explorerforum.com/forums/showthread.php?t=321591
     
  7. SuperKirby

    SuperKirby Active Member

    Joined:
    June 23, 2012
    Messages:
    205
    Likes Received:
    0
    Trophy Points:
    0
    City, State:
    Central MN
    Year, Model & Trim Level:
    1993 Explorer XLT
    Thanks! I'll make some calls tomorrow on my day off.
     
  8. jmdirk

    jmdirk Active Member

    Joined:
    July 22, 2004
    Messages:
    238
    Likes Received:
    11
    Trophy Points:
    28
    City, State:
    Ottawa, Canada
    Year, Model & Trim Level:
    '93
    Being Pre ODB you should be fairly safe with the universal cats.

    I've heard several instances of OBD cars being unhappy with universal cats. If the flow rate through the cat doesn't match the OEM unit, the down stream O2 gives readings outside the calibrated range for the CPU and you end up with a check engine light. A friends 350Z had this problem and I had the same issue with a supposed 'high flow' cat that I bought for a Civic.
     
  9. Punjab

    Punjab Member

    Joined:
    February 17, 2009
    Messages:
    78
    Likes Received:
    1
    Trophy Points:
    0
    City, State:
    Colorado
    Year, Model & Trim Level:
    '94 Limited
    I actually just added the KKM filter and adapter and being the first "performance" modification I've done all I can say is wow. I didn't think the sound from the 4.0 V6 was worth listening to but that simple mod clearly made a major difference.
    I have to assume it's getting more air in because more sound is certainly coming out during WOT.
    I definitely recommend adding one.
     
  10. SuperKirby

    SuperKirby Active Member

    Joined:
    June 23, 2012
    Messages:
    205
    Likes Received:
    0
    Trophy Points:
    0
    City, State:
    Central MN
    Year, Model & Trim Level:
    1993 Explorer XLT
    Good to know. I ended up working extra the last couple days so no time to make any calls to exhaust shops. I'll try Monday or Tuesday.
    As for the kkm kit, I suspect I'll end up ordering one. I have a couple other irons in the fire so waiting to see what plays out.
     
  11. 2stroke

    2stroke Elite Explorer

    Joined:
    August 7, 2013
    Messages:
    1,173
    Media:
    6
    Likes Received:
    35
    Trophy Points:
    68
    Location:
    55302
    City, State:
    Annandale, MN
    Year, Model & Trim Level:
    1993 Ford Explorer Sport
    I find a wire feed welder to work great. I have a friend who has one that I use from time to time. I'm sure theres a muffler shop in St Cloud that would put it on cheap for you.
     

Share This Page







We Support Our Troops!