Exhaust popping and very slight smoke from exhaust

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underworld1001
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Exhaust popping and very slight smoke from exhaust

Postby underworld1001 » Sun Mar 22, 2020 12:13 pm

Hey all,

So I was driving the other day and stopped to get the mail. I noticed an odd sound from under the hood, kinda like there was a SLIGHT exhaust leak. I figured as much and drove it home. Checked it out when I got there and there couldn't find out that would point to where it exactly was, other than it sounded like the drivers side exhaust manifold/cat area. I parked it and haven't moved it in about 2 weeks since then. This morning I took another stab at trying to figure out where it was and drove it around the block. I accelerated a little hard and heard a pop and the exhaust suddenly got much louder. Took it home and revved the engine a little bit and heard popping in the exhaust, similar to open exhausts when the engine is revving down. Not sure where to start on getting this fixed and sure don't want to just throw parts at it. I'm getting no error codes at all so I'm guessing this might not be the cat. Honestly just don't know. Any help is appreciated in advance.

Thanks!


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smj999smj
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Postby smj999smj » Mon Mar 23, 2020 6:04 pm

You might try removing the wheel and plastic wheel liner to get a better view of the exhaust manifold. Most of the time they crack around where the flange is.

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underworld1001
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Postby underworld1001 » Mon Mar 23, 2020 7:05 pm

Wouldn't that trigger a code though? I'll see if I can tear it apart little by little this week. Manifolds don't look too expensive. If it is the manifold, have you heard of any issues with aftermarket ones? Drivers side initially looks like more of a pain than the passenger side, but I'll figure it out once I dig in.

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Postby smj999smj » Tue Mar 24, 2020 4:45 am

Actually, the passenger side is the worse because you can't get the heat shield off in one piece unless you lift the engine off of the mounts. When I installed my Doug Thorley headers, I had to cut the shield into pieces to remove it without lifting the motor. On the driver's side, you can pull the heat shield out through the top once you get it unbolted, if you have to remove the manifold. I haven't heard of any problems with the aftermarket manifolds. You will need to remove the secondary converter out of the way and remove the header from the bottom to get it out and in. Another thing, it's not uncommon for the heat shield bolts to break while trying to remove them, as they are only 6Mx1.0.

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underworld1001
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Postby underworld1001 » Mon Apr 06, 2020 10:04 am

Ok, so I manged to dig in and find out what the issue was. Apparently the flange between the exhaust and the manifold just snapped. Looks like a clean snap too. I'm having a hard time getting the stuff out. As rusted as it looks, I'm tempted to just cut the pipes out, but I'd prefer to keep things as clean as possible. The bolts all came off fairly easily using some Aerokroil I had around. Great stuff. The rear O2 sensor is in such a crappy place I'm having a hard time getting it unplugged. The primary and secondary cats are still connected and look like a serious PITA to remove. No air tools here at the moment to help either.

Anyone know of a easier way to remove the piping vs cutting it all off?

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Postby smj999smj » Mon Apr 06, 2020 4:53 pm

They way I would handle it is I would remove the front converter (which would require removing the rear converter, as well, soak the nuts/studs down with rust penetrant, wire brush the nut and threads, and use a torch to heat the nuts and remove them.

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underworld1001
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Postby underworld1001 » Sun Apr 19, 2020 8:55 am

Ok so I got a exhaust manifold ordered from Advance Auto Parts. If the order was online I get 25% off so obviously thats the way I went. A little over $45 off so can't complain.

As far as the cats go, I can't get the nuts/bolts loose. Due to how it snapped both cats want to move when I try and turn. I'm just going to cut them off and replace the cats with some inexpensive ones. I will probably cut the behind the flange of the secondary cat so I can save myself the expensive of buying a new front one. Trying to complete this for less than $500.

I was looking at emissions and checked my vehicle. Just so I'm not mistaken, I need CARB cats right? If so, that's a little odd. The vehicle was originally sold new in Massachusetts. The original owner just traded it in when they moved to Texas where I picked it up. Regardless, just looking for confirmation or possibly a way to confirm via Nissan.

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smj999smj
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Postby smj999smj » Sun Apr 19, 2020 12:09 pm

Your vehicle is California emissions certified, but you only need to purchase C.A.R.B. certified converters IF your state uses those standards for state inspection. If you live in Texas, you don't need to worry about it.

The states that accept California emissions standards are Colorado, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington, as well as the District of Columbia.


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