Leaking Cat Converter

Ifixyawata · Post by **Ifixyawata** » Wed Mar 13, 2013 3:13 am

My exhaust is leaking badly behind the square flange but before the catalytic converter... I'm gathering from my reading on here that this area of the exhaust was at one time a flex joint. It's coming apart probably due to the fact that I've broken and repaired (read: coat hangers) several exhaust hangers and for a period of time the muffler was hanging down putting a pretty severe twist on the whole system. I'm looking for the cheapest easiest way to repair this. This car is beaten pretty badly at this point and I'd just like to get the p2096 code to go away and I'd also like to reduce the amount of CO the heater sucks in through the cowl. Do I have an option besides replacing the cat converter entirely or getting that joint welded up?

mopar2 · Post by **mopar2** » Wed Mar 13, 2013 9:26 am

You can get another cat, you could get a ebay catless downpipe. Those are about your only options. Don't get the catless downpipe if you have vehicle inspections. They are not obd compliant due to not having a cat.

r/tguy02 · Post by **r/tguy02** » Wed Mar 13, 2013 12:17 pm

if its just a crack, you could try JB weld, probably hold for a lil while till you can gather enough money for a new cat

Ifixyawata · Post by **Ifixyawata** » Wed Mar 13, 2013 12:44 pm

I'm not too opposed to the catless option I just have concerns about reduced fuel economy. I've already read about the use of non foulers etc.

mopar2 · Post by **mopar2** » Wed Mar 13, 2013 8:13 pm

I don't think fuel economy will be affected to much. I removed my cat off my first 98 and the mileage actually went up. It surprisingly gets 30 mpgs with a 3spd. My 01 gets 24 with the same 3spd.

Ifixyawata · Post by **Ifixyawata** » Wed Mar 13, 2013 9:24 pm

That sounds like good news then, Ive been eyeing up a header and downpipe on ebay thats a little under a $100. That should be easier than dealing with those rusted flange studs and everything. Anyone have any experience with these headers? I didnt see a brand name, I will post a link later when im not on my phone.

Post by **occasional demons** » Wed Mar 13, 2013 11:10 pm

You could just weld in a replacement flex joint. But you will probably have about the same as an Ebay header into the repair.

The oem flex joint is pretty restrictive as far as I.D. goes. It is actually 2" or maybe a shade less. A larger I.D. flex joint on the oem converter would probably give you the best of both worlds, for folks where passing emissions is an issue. Or you don't want to chance the non fouler not working...

The better ebay headers have the same 4 bolt flange set up. The ones with the friction fit built in flex coupling, I wonder about.

An OBX is probably the best overall bang for the buck. You also want one with the o2 in the collector, not in the primary tube. If you have a bad injector in a cylinder that is not on that primary tube, the o2 will never see it. So the PCM will not see a lean, or rich condition.

Ifixyawata · Post by **Ifixyawata** » Thu Mar 14, 2013 12:30 am

Here's a link to the header I'm looking at:

http://www.ebay.com/itm/00-05-DODGE-NEO ... 5c&vxp=mtr

From looking at pics it looks rather like an obx to my untrained eye. Anyone used one of these? Also, will there be any other adverse effects of removing the cat besides the chance of an annoying CEL?

mopar2 · Post by **mopar2** » Thu Mar 14, 2013 10:14 am

That's about the right one you wanna look for!

ragek23 · Post by **ragek23** » Thu Mar 14, 2013 10:04 pm

I have a vibrant $80 HFC welded in my downpipe. Nice cheap solution but its a bit loud. not any worse than yours leaking now tho.

Ifixyawata · Post by **Ifixyawata** » Sat Mar 16, 2013 12:33 am

OK.... a lot of eBay listings say 2000 to 2004 and only a handful say 2000 to 2005... there's no one year difference that only affects 05s right?

ragek23 · Post by **ragek23** » Sat Mar 16, 2013 3:56 pm

correct 00-05 are all the same

NickKo · Post by **NickKo** » Sat Mar 16, 2013 4:12 pm

r/tguy02 wrote:if its just a crack, you could try JB weld, probably hold for a lil while till you can gather enough money for a new cat

I doubt that JB Weld would work / live, in such an environment.

I know, I've tried doing this, on my old Slant Six.

- Nick

Ifixyawata · Post by **Ifixyawata** » Sun Mar 17, 2013 3:29 am

Yeah I'd probably have had to use up all my jb weld to close that opening anyway...

Anyone know what a stock muffler sounds like with a header and no cat in front of it? I'm guessing it'd have to be a little louder than stock huh? Besides... there's nothing wrong with my stock muffler besides it's propensity to fall off every six months because the Cintas hangers have rusted again.

NickKo · Post by **NickKo** » Sun Mar 17, 2013 1:15 pm

Ifixyawata wrote: Anyone know what a stock muffler sounds like with a header and no cat in front of it? I'm guessing it'd have to be a little louder than stock huh?

Yes.... A Neon will sound sort of 'ricey' and will 'drone' with just a muffler and no cat converter. ( I know, I tried it for 3 days..... I hated it.)

The converter acts like a resonator, to help quiet down the exhaust.

- Nick

titansxt · Post by **titansxt** » Mon Mar 18, 2013 11:59 am

I had this happen so I just grabbed a cat from Rockauto for ~$150. I thought that was a fair price.

Skitlz · Post by **Skitlz** » Mon Mar 18, 2013 12:59 pm

I have a shorty header that could be the same as the link or at the very least a clone. The weaved part so it can flex shows no signs of damage after two years or so.

With that header and no cat, it will be louder and sound like a lawnmower/go-kart. I'm not very concerned with how my car sounds, so it doesn't bother me. With a new muffler it's a bit less of a lawnmower but it's still not what you might call a pleasant sound.

You can add a resonator if the sound bothers you too much. A friend suggested I put the straight version of the Thrush Turbo muffler in line (not where the muffler actually goes) to accomplish this. I couldn't tell you if it's effective or impacts performance because, as I said, the sound doesn't matter to me.

Be warned, though, that the bolts involved with replacing the exhaust manifold may be incredibly rusted. I joined Neons.org (which later led me to 2gn) just to figure out what to do about the immovable bolts.

Ifixyawata · Post by **Ifixyawata** » Mon Mar 18, 2013 1:36 pm

Yeah... regarding those bolts I think I'm going to start with applications of PB blaster a few days before the parts get here. Hopefully a few heat and cool cycles of the exhaust with a nice coating of penetrating oil will make them ease out better... I hope.

Skitlz · Post by **Skitlz** » Mon Mar 18, 2013 3:17 pm

Ifixyawata wrote:Yeah... regarding those bolts I think I'm going to start with applications of PB blaster a few days before the parts get here. Hopefully a few heat and cool cycles of the exhaust with a nice coating of penetrating oil will make them ease out better... I hope.

Try a few weeks. That's how long it took to get that thing off for me. And even then I ended up using a saw-zaw for some of it.

Ifixyawata · Post by **Ifixyawata** » Mon Mar 18, 2013 5:14 pm

Are you talking about the bolts holding the manifold on or the four studs on the square flange?

Skitlz · Post by **Skitlz** » Mon Mar 18, 2013 7:31 pm

I was talking about the flange. The manifold bolts came off eventually at the cost of flesh and blood (literally).

Ifixyawata · Post by **Ifixyawata** » Mon Mar 18, 2013 8:25 pm

I wholeheartedly welcome some busted knuckles

Post by **occasional demons** » Mon Mar 18, 2013 9:57 pm

I would think the stock muffler would sound pretty quiet regardless. I know my '01 SE muffler was way too quiet. If not for the oil light, you couldn't tell if the car was running or not.

On mine, the manifold to head bolts didn't give me much issue. The flange nuts were good except for one, that I had to painfully hacksaw the nut enough to get it to break free with a chisel. IIRC, the bottom one that the bracket is attached to.

The studs for the flange are still available from the dealer. The actual stud does not turn, yes, it has a hex head. But you will not turn it. Just turn the nuts. If you replace them with bolts, then you will have even more fun trying to put it together, let alone get it apart again.

On my DOHC OBX (PT) header, the factory studs were too small to have a press fit into the header flange. But they were perfect in the downpipe. So I put the nuts on the top side. Worked out better than the stock set up IMHO.

And oddly enough it has no cat, just a Vibrant resonator and an unknown Magnaflow DOHC muffler in the back that is more of a show piece than a muffler. It doesn't really drone, not like the '01 with a cat, and a real muffler. Is it still loud as hell under load? Yep.

Skitlz · Post by **Skitlz** » Tue Mar 19, 2013 1:24 am

Ifixyawata wrote:I wholeheartedly welcome some busted knuckles

Only way to do it!

Ifixyawata · Post by **Ifixyawata** » Tue Mar 19, 2013 1:34 am

I'm probably being paranoid but all the extra heat/exhaust gas coming from the leaking joint shouldn't hurt anything right? Like the steering rack for example?

Post by **occasional demons** » Tue Mar 19, 2013 7:42 am

If the crack is pointed straight at it, and you sit and idle for hours, probably. Moving down the road, there should be enough air movement...

Ifixyawata · Post by **Ifixyawata** » Sat Mar 23, 2013 4:29 am

OK I got the eBay header today and I've found that there's no gasket for the square flange... is this a common size? Is it the same as the OE gasket? I'm not waiting for the seller to replace it..And what's the deal, it looks like the holes in the header flange are threaded?

Ifixyawata · Post by **Ifixyawata** » Sat Mar 23, 2013 9:04 pm

Alright, figured out that the stock OE gasket is a fit... Only have the old manifold and cat out so far... rusty bolts and heat shields be damned! A couple questions... as of right now I can only account for 7 of the 8 manifold bolts, these easy to replace?

Also I noticed that the hot leaking exhaust burned through the plastic wire harness cover on the RH side of the engine on the back side, but all the wires inside still look well insulated. While looking through this I also noticed that there's a sensor on the back of the block, I'm guessing it's probably coolant temp or maybe oil pressure? I was alarmed to see only one wire coming out of it... did I rip a wire off somewhere? I felt around and there are no stray wires that I've found. I also broke the cruise vacuum hose in a couple places. I figure that can be replaced with regular vacuum hose, too.

The good news is the upstream O2 sensor came out ridiculously easy, bad news is the downstream one is still stuck in the cat convertor and its rounded off from an open end wrench followed by a pair of vise grips. Probably going to end up having to just get a new one, but oh well.

One last thing, will I need any kind of heat shielding on anything else in that area besides the wires I mentioned earlier?

Post by **occasional demons** » Mon Mar 25, 2013 8:10 am

Heat shielding for the harness. The one wire plug, if it is green, is the oil pressure switch wire - normal.