Catalytic Converter Heat Shield: Necessary Or Not?

My 2002 Honda Civic was whistling (kinda like a slide whistle) while the car would idle and the A/C was on. I finally took it to get checked after over a year of this odd noise, and was told that the bolts that hold the heat shield for the catalytic converter are cracked/beyond repair, and it is loose and makes that noise. They said I can bring it in and they will remove it for me if the noise bothers me; otherwise, I can just leave it go.

My issue is that about 2 years ago, I had my catalytic converter replaced by an independent mechanic because it was cracked. Apparently they never put the heat shield back on when it was replaced, because when I took it to the dealer a month or two later, they told me it was missing and should be replaced. I let them replace it while they replaced a brace that held the catalytic converter in place that had cracked.

So, one Honda dealer told me that the heat shield is necessary, and the one I took my car to today told me that I could remove it and not have it replaced. I’m more apt to trust the current dealer that I take my car to (sometimes), but I wanted some more opinions. Thanks.

It’s generally a good idea to have the heat shield completely intact, because it gets to be the hottest thing on the entire car. Temperatures can get beyond 600?F and if the heat shield is missing, a fire hazard can be created. If the top part of the shield is missing, the carpet inside the car can get charred and catch fire. It also serves to protect other things near the converter from getting damaged by the heat.

One of my favorite responses to this type of question is they did not put that there for decoration, it serves a purpose.

So I suppose I should have it replaced. I’m pretty sure it’s not the top heat shield, and I don’t know why things related to the converter keep breaking. I guess I shouldn’t complain because it has 176,000 miles on it, and it has otherwise been very reliable. Thanks for the advice.

What I would like to know is, where does one go to get a replacement heat shield for a catalytic converter for 2002 Honda? When the heat shield is part of the catalytic converter itself?


It depends on where the heat shield is located. If it is between the body and the converter, its absence might be important. On the other hand, if it is below the converter, you don’t need to worry. Just don’t park the car in tall, dry grass.

From time to time, a lower heat shield on our Subaru will begin to vibrate. We report it to our mechanic and he chops of the offender. No problems, so far.

Why should you replace a perfectly good catalytic converter heat shield? Let an independent mechanic put a wire, or metal band, around the shield to keep it from rattling.

Perhaps it is a different heat shield in the near vicinity of the catalytic converter. It was replaced before… or something was supposedly replaced two years ago. I would have to dig out the records to see exactly what heat shield they are referring to.

Honestly, I don’t care much if it shrieks, whistles, or rattles. The ones under my car rattle a bit sometimes, and it doesn’t bother me. I just don’t want bits of my car falling off or out.

That’s what the proposed steel wire (or, metal band), wrapped completely around both halves of the cat. heat shield, is for: to keep the shield from falling off.
And, it will keep the shield in place, doing it’s intended job.
And, it won’t fall off. It’ll stay there for years and years.

It will fall off and add road hazard for someone else. Mickey mouse solution won’t work in this case. Rip it off or have it welded properly(very difficult).

I’ve had great results with a HUGE metal hose clamp. Tighten it up good. Worked on my wifes 87 Accord. I think it was on there for well over 4 years with no problems.

I think it is necessary. I would either get it welded in place or clamp it with hose clamps as MikeInNH mentioned.

Budd2049, this catalytic converter is under the hood, not under the car, so the carpet won’t catch fire, but the hood might heat to the point where the paint burns off or bubbles and peels.