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Discussion Starter #1
When riding the LT hard and keeping the rev’s up using a lot of engine braking, every so often I get a very loud backfire with the throttle closed, but not all the time,
will only backfire once, very loud, like having a shotgun going off?
Exhaust system seems ok, no leaks round the head or anything, anyone get the same?



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Mine will do that going over a mountain road. It will get hot going up it and once I start going down and roll off the throttle it will at times back fire. I can "for fun" burp the throttle just lightly and then roll off to make it louder. Great for tailgaters.
 

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Speculation on my part but I believe the LT disables the fuel injectors when the throttle is rolled off down to a preset RPM. Any unburnt fuel from the transition would ignite when it hits the catalytic converter which is at high temperature from the high RPMs. Generally speaking full throttle equals full rich on the mixture for maximum horsepower in any vehicle. That's why police cars stink so much when they pass you at 90 MPH or so. On that note, never park your Crown Vic in dry grass after a car chase. Trust me on that. :D
 

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Yep mine does it too, specially using engine breaking on these Welsh hills.
The UK catalytic converters are in a different place to the US ones, so I am not sure if they will react the same if it is that.
 

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;) Mine does it too. Mostly if I go to pass in 3rd gear and run the speed up to around 100 mph then hard engine brake to back around 65. It does keep the locals off my tail light.
PS. no cat.
 

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Discussion Starter #6
Ok, thanks’ all, :toast:
I was a bit concerned it may be a fault in a valve or something, or blow the head gasket.. :kaboom:
 
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