Timing Belt Replacement
If it has never been done, right now.
Yeh, that's a 80-100 recommended service. It's not a hard job though, easy access, so it shouldn't cost too much.
2006 Rav4 has a timing chain, not a timing belt. There is no recommended replacement interval for the timing chain. It is possible for them to become stretched, but that would most likely be in the 200,000+ miles range.
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