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I was just wondering why my Flows (with H pipe) pop and crackle when I let of the gas. I recently heard several more that do the same thing.

Is is because of the reduced backpressure in the system? Bigger chambers in the muff?

Just wondering,

Clint
 

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i suspect you have a leak in the system, becuase not all aftermarket mufflers do it, not even all of a certain brand, but if you have the air tubes still hooked up or a leak upstream it'll pop on decel. Not sure why.
 

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Discussion Starter #3
Thanks MFE,

I just assumed they all did it. I do have the tubes connected and I might have a leak as well. I still have the original headers on my '90. I don't think they have ever been off and they might be leaking a little.

Good to know that the muffs aren't supposed to do that.

Thanks,

Clint
 

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I'm not by any means an expert on this, but my guess would be...

Do you have an offroad h-pipe? My understanding on this is the Catalytic Converters stop any backfires (or popping) through the exhaust. Which would be why you didn't see/hear/experience this with factory exhaust (with cats) and are now with aftermarket exhaust (no cats).

This may not be the case, but it's my take on it.
 

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I have an off-road pipe with the air pump system disabled and disconnected and mine don't pop at all, but I remember back 18-20 years ago popping 5.0's were rampant because everybody messed with their air pumps and cats. If you keep the air pump system intact without the cats it'll pop and burble.
 

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You've got a good point. When I had my air pump hooked up with no cats, the car popped and burbled all OVER the place. It was every time I let off the gas (even from light throttle applications). Without the air pump hooked up, this problem went away.

Also, when I had the Speedbrain in my car it would pop after I let of the throttle from a wide open throttle. I'm sure this had something to do with the amount of timing or fuel I had in it.

The Air pump is probably the problem in this case though.
 

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I have no air pump and no cats on my car and it pops and crackles ALL the time. It didn't do this as bad before I had this new camshaft put in.

While the car was down for the cam I had my tranny rebuilt so the X came off. Maybe it wasn't reconnected properly.
 
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