Something fell off!

[Q45Viper]

Just came out of a car wash and heard what was definitely a metal piece dragging. Pulled over, sure enough, still being held by what looked like a cable around one nut, I cut it off with a cable cutter I had with me threw it in the trunk and proceeded home. My guess is this is a heat shield for the catelytic converter, about a foot long, rounded in oval shape with what looks like straps welded and bolted to it and multiple holes in a grate like pattern. Looks like metal fatique or rust on the straps caused the failure. Located under the area just in front of or underneath the passenger front seat. Am I right about what it is and is there any problem driving without it for 2 weeks when the car is scheduled in to the dealer. I have heard some interesting stories about cats overheating and this is my concern.

[Q45Viper]

I just thought of something, this couldn't be the bottom half of the cat and it came apart!? Tell me that ain't it guys? It kinda does look it could be half of something?

[Q45Viper]

I just got a mirror and jacked it up a little, both sides look the same, it looks like it could be a cover for what looks like round "precats" for lack of the right word, the cats appear to be further back and are larger flatter pieces? Maybe I lost the other one earlier, kinda weird, definitely from my car as it was still attached. Any ideas?

[Q451990]

Your car has pre-cats built in to the exhaust manifolds near where the bell housing and transmission bolt together. Then catalytic convertors (I think this is the heat shield that fell off of yours) then two mufflers (that you reference in your last post), then the resonator in the back.

The only thing that seems a little odd to me is you said both cats look the same. The bottom heat shields are bolted on to the cats with sheet metal screws, so I'm not sure about these straps you're talking about. Do you have a digital camera that you could take pictures of this part and post it here?? Maybe it's something you picked up on the road?

I don't think the cat split or you'd have some really bad exhaust noise!

Heath

[Q45Viper]

Not something picked up, was still attached by a wire cable around one of the nuts. I did not mention mufflers, they are way in the back of the car, right? This thing was hanging still attached by a cable to a nut, the nut was on the dragging piece underneath the front passenger seat. It is about 12 inches long, maybe 4 inches wide, it looks like it could fit around the precats except there is no matching cover on the other side. Very sturdy looking piece with lot's of what look like cooling vents or holes in it. I would have solved it by now except there is no matching piece on the other side. Digital camera is down for repair. Just for reference though..... precats first coming right off the manifolds, the big cats both sides probably to the rear of the front seats then mufflers aft of that right? Everything dual? Amazing how good everthing looks under here at 133k, except for the falling off stuff. And kudos to Infiniti for making good stuff, I dragged this thing for a couple miles it still looks good enough to reinstall.

[Rex]

Sounds like it may be a "heat shield". They were added to cars to keep the HOT cats from starting fires if you pulled off the road into the grass.

[Q451990]

Have you used your emergency brake since this episode? The only cable and nut I can think of would be in that area.

Heath

[elwesso]

On the passenger side cat, there is a ground screw going into the heat shield..... I had woes with that!!! It must have been holding on by the ground wire and by the screw.....

Thats what it is.... I feel like Q45tech knowing the answer definitely!!!!!! :blue :fruit

[Q45Viper]

That's exactly what it looked like, the wire I cut. And in retrospect the radio was acting up. That kind of ground, for the radio? Now, is this shield for the precat or the cat? Again, location was underneath or just forward of the passengers seat. And, anybody see any problem with driving it a bit before it goes back on. Still find it strange that I can't find a match on the other side.Elwesso, what problems did you have, now that I cut this thing, I probably have the same problem.

[Q451990]

That's right... forgot about the ground strap. Wouldn't think it has anything to do with the radio. Mine has been missing on Q1 as long as I've had it.

Shouldn't be a problem driving it w/o the heat shield. The bottom one is more to protect anything near it (like tall grass if you're out driving around in the fields or something) - not a big deal. My guess is that your other heat shield is missing too if everything looks the same under there.

BTW what you're describing is the cat. convertor, not the pre-cat.

Heath

[elwesso]

Its for the cat..... No big deal on driving it... Just dont park over any leaves or anything that could touch it and ignite...... Personally, i wouldnt even bother replacing it....... Its not that crucial of a part....

Since you cut it (unforunately, bad move), you are going to have to find where it sources and put a new wire in.... Or, at bare minimum, strip the wires and stick it to the body...... And its on the cat, not the precat......

What happened to me, is the heat shield was rattling, so I went in and tried to unscrew it and it was so rusted it just twisted....... I had to implement a new screw and some loctite, and it was golden..... I used a screw that was too long, so it is acutally touching the cat a little bit, enough to put pressure on it so it doesnt rattle......

[elwesso]

Its kind of one of those things thats is nice to have, but you dont need it...... I wouldnt waste the money, with the expense of parking on leaves or driving in tall, dry glass.........

[Q45Viper]

You guys are great, now I can fry some weeds in the driveway! Last question...What the heck is the ground strap for? And the consequences of not having it? I cut it off real close to the shield and I still have the shield so I'm guessing I can make everything go back together, but why should I care about the ground, what is it for?

[elwesso]

Its just a ground wire, they're all over the body..... Im not sure if thats specific for something..... but I would just strip off some of the wires and stick it somewhere on the body....... Its not even that big of a deal, maybe just let it be a dangler!!

[squeefoo]

I've thought for awhile that exhaust should be grounded so the loose ions (from acidic activity) have somewhere to go. They can't go to the engine ground since the headpipe(s) and headers are hot (too much resistance). So it seemed to me that ionic activity promotes rust, Mazdas (older ones) are horrible for this, and I've noticed they have no ground, just rubber donuts. However other cars have the same thing and don't rot! Stainless? -Squeefoo