Catalytic converter hell

[csigona]

Howdy, folks. I've got a 1999 3.0L Ranger flex fuel, 112" wheel base, automatic. My trouble is the forward Y-pipe double catalytic converter. I tried to replace it with a bolt-on replacement. The first try was a Magnaflow 447189. It's listed as CARB compliant and supposedly fits both 3.0L and 4.0L engines. It doesn't fit my 3.0. The left side fits the manifold, the right side is 4-5" too short and bent lower than the original. The rear flange is good. Next try was a DEC FOR20433, federal compliant, which supposedly fits 1998-2003. It fits both manifolds, hallelujah, but the rear flange is too big. Apart from cutting and welding, I don't know where to turn. Knowing how deep in trouble I've gotten myself, and how much time I've burned, I should have brought the Y pipe to a muffler shop and have him cut out and replace the bad converter, but I cut up the original to take it out more easily. I guess a good welder can probably put it back together.

Can anyone tell me what the story is with all these variants? I can't afford to keep buying expensive parts that don't fit and are difficult to return because I've partially installed them.

 

[19Walt93]

Flex fuel has a bunch of unique pieces and I've found that sometimes California compliant engine have different exhaust manifolds. If you have one that fits on the manifolds and lines up with the exhaust, I'd change the flange on the exhaust and bolt it up. It's 21 years old and some stuff is going to be really hard to find.

 

[55trucker]

If you have what's under my 98 then the aftermarket assumes that you're going to replace the intermediate pipe behind the cat assembly as well. The OEM cat assembly is all welded back to the intermediate pipe ball & socket flange in front of the muffler. The aftermarket however doesn't manufacture this portion quite the same as the OEM assembly. They don't include the intermediate pipe with that ball & socket flange as part of the welded cat assembly. Seeing as the OEM muffler is welded to a 12" inlet pipe (which has a ball & socket flange) one has to either cut the old pipe just in front of the muffler & slip in the new replacement pipe (weld) or retain the original ball & socket joint & cut the new replacement intermediate pipe & weld on a new ball & socket to mate to the original ball & socket.

Walker, AP, Eastern didn't think this out very well.

 

[csigona]

Thank you for your replies, 19Walt93 and 55trucker. I'm giving it yet another shot, this time with AP 642016. The photos look good, both at the manifold ends and the output flange, but I have to say that with each lesson learned, I focus more on particular aspects of the photos, and could easily miss other important details. I'll report back in a few days when it arrives.

 

[csigona]

It fits! It took a little banging and tweaking, but it fits, and that's good enough for me. To anyone starting a similar project, I suggest you carefully study the manifold ends and the rear flange end, and compare them to your original. Don't go by the charts of what fits; go by the photos. I would have saved a lot of headache if I were more careful with the photos. Another point, although one I couldn't take advantage of, since the Magniflow unit didn't fit, is that the Magniflow is far better built than the AP or DEC brands. It also costs more. And finally, if you're good at welding, you'll save time and money by just cutting out the bad converter and welding in a universal one. If you don't know how to weld, you'll have to try the specific bolt-on units like I did. I'm going to practice welding on the old unit before I scrap it. I want to be ready for next time.