09 4Runner 4.7L V8 Coldstart Knock

[rgwest61]

For past 2+ years I have been experiencing a knocking noise at coldstart mostly during cold months in Colorado. What is interesting is the rhythmic interval of the noise increases when turning the steering wheel to make a turn. The noise eventually goes away once engine warms up, and does not occur again at later start ups during the day even if engine completely cools down. I have read posts that such issue could be due to bad fuel injection pressure regulator damper, or cracked exhaust header manifold. I am not interested in putting $3000+ to replace both manifolds, and will sell/trade-in my 4Runner if such is the case. Thoughts?