My 2000 F150's V^ 4.2L exhaust system is plagued by a noisy exhaust system. It pops and cracks loudly when warming up while driving and does the same when it is turned off. The truck has 42k miles on it and the noise started when a new engine was installed at 30K miles. It sounds like it may be coming from the catalytic converter. It is a metalic sound that seems to be expansion then later contraction of connected pipes, etc. What can I check to see if this can be corrected?
Is the exhaust system tightened incorrectly?
Could it be coming from the heads of the new engine?
Thanks,
GR