2009 Subaru Legacy metallic rattling in engine compartment

2009 SUBARU LEGACY
98,000 MILES • 2.0L • 4 CYL • AWD • AUTOMATIC
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LMUTARELLI
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I replaced the plugs in my car about a week ago due to misfiring. I bought the car used with approx 57k miles, so I figured it was about due since I was at 97k. Once I replaced the plugs, misfiring went away, but a few days later when I started my car I heard a metallic rattling until the clutch kicked in and than idled fine. Once I started driving, between 2-3000 rpm's in first and second gear only. Once I get into third and higher it goes away.
Mar 30, 2015 at 6:16 PM
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JACOBANDNICKOLAS
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Has the misfire returned? Have you checked for loose heat shields?
Mar 30, 2015 at 7:41 PM
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LMUTARELLI
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Misfire has not returned since replacing the plugs. The car runs normal except for the rattle. Was thinking that but, didn't look because wasn't anywhere near it. I was also thinking maybe the catalytic converter may have gotten damaged because I had to drive about 15 miles with the misfiring before I got the car home. Is that a possibility? I haven't really notice a lack of power from the car. It seems pretty good on the response when I hit the gas.
Mar 30, 2015 at 7:48 PM
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JACOBANDNICKOLAS
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Most likely it's a heat shield. However, I have seen the insides of the catalytic converter come loose and rattle. Take a rubber mallet and tap on the exhaust to see if you can duplicate the sound.

Just as an FYI... Replace the timing belt on this vehicle at 100K miles. Most times I replace the water pump too since it's right there.
Mar 31, 2015 at 6:02 AM
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LMUTARELLI
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Ok, thanks. I will try the rubber mallet and see. As for the belts, I just had them replaced at 80k miles because the grooves looked worn. Thanks for the heads up on that and how to check the cat.
Mar 31, 2015 at 6:07 AM
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JACOBANDNICKOLAS
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Are you referring to the engine timing belt or the accessory drive belts that run the alternator, ac...?
Mar 31, 2015 at 7:39 AM
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LMUTARELLI
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Not sure, I will have to go back and ask the person that did it. I asked him to replace the belts, I just assumed he did that. I will double check with him. If he didnt, ill do it at next oil change which is due at 100k miles.
Mar 31, 2015 at 7:45 AM
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JACOBANDNICKOLAS
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Just so you know, replacing the timing belt is about a 500 dollar job. It's not a quick process.
Mar 31, 2015 at 8:49 AM
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LMUTARELLI
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yeah, i am aware, lol. But unfortunately, a necessary evil. Thanks again for your help. i have an appt with the dealer scheduled for tomorrow to take a look at the rattling noise. Im hoping tonight when i get home to look at the suggestions you gave me and point them in the right direction so they dont try to get me for something i dont need
Mar 31, 2015 at 8:52 AM
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