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Old 09-15-2015, 03:33 AM   #404
solidONE
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Tip in knock or exhaust rattle?

Here is a log I took after (re-re-re)installing a somewhat ill-fitting front pipe (j2 70mm) that doesn't have provisions for the stock doughnut gasket.

http://datazap.me/u/solidone/fp-no-o...=0&data=1-5-12

As you can see, a stupid amount of knock at tip-in and upon throttle closure.

Here's another log I took after having really torqued down the catback to front pipe connection.

http://datazap.me/u/solidone/tip-kno...=0&data=1-5-12

tip-in knock still present. I checked all the connections for leaks and was not able to locate any.

Now, I recall a long while ago there was some discussion about "phantom knock" on these boards. After having taken these logs, I'm suspicious of the vibrations in the exhaust system upon sudden load increase during low RPM operation being mistaken for engine knock by the ECU. What are your thoughts?
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