I have a 2011 camry SE 4cyl with 90K miles. thinking I should replace the serpentine belt. two issues and frankly I'm confused.

a. I can't locate the 19MM nut for belt tensioner. Viewed camry forum you tube video - but I can't locate same tensioner on my car. My tenisoner looks more line a 2012 model. Can't locate engine code. Mfg date was 12/10.

If I follow instructions for the 2012 model year I would have to take off the other belt.

b. Should I replace the other belt as well?

And if someone could provide a link to belt diagram it would be appreciated.

Thanks for the help.