My 2010 has both bolts (1 on either side of the sensor).
I believe in 2011, the bean counters hired by FMC got involved, and began figuring out how to reduce costs (.01 here, another .01 over there, etc,) and dediced to lop off one bolt from that model year and onward.
No real reason other than that.
If they save the cost of the bolt, the cost of drilling/tapping that 2nd hole, as well as the time it takes to fasten/screw that bolt down, or the time to drill/tap out the hole to, etc. etc.
You multiply that, by however many 3.5 Eco motors produced....
And you save a lot of money.
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