That line should be marked blue and is the fresh air line from the turbo control valve (TCV). The yellow marked line should go to the waste gate. The TCV should be mounted on the airbox near the bottom of the passenger side.

http://ww2.justanswer.com/uploads/JC/jcjcrespo/2013-04-30_195951_s60_t5 ...

That is the compressor bypass valve, or CPV, yes there is the option for a blocking plate, but you will need to install an external valve.
Here is the information page from IPD.
http://www.ipdusa.com/products/10007/12 ... -off-plate

When I bought my radio only two lights worked in it.

This will show both how to replace the button lights and the screen lamp.

1: Use a coin to pop the latches out.
IMG_20150727_182843[1].jpg

2: Pull on the latches to remove radio
IMG_20150727_182855[1].jpg

3: Remove the volume/balance knob ...

If I'm not wrong the plate is near your O2 sensor plug on the firewall. Down and to the right of where the brake booster mounts with the four holes around the circular cutout. On the inside you will have to cut away some of the rubber to get to the bolts. They typically have some markings where they ...

I have gotten spoiled with mine it would seem.

PNP is mounted to the top of the transmission where the shift linkage connects. https://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=29930

All depends on how much stuff you want to have around for a just in case, what do you plan on doing with the car is it a daily driver, or a thrash ...

This is the one I have and use when I measure runout just find a chunky piece of metal typically the caliper bracket and adjust the goose neck, https://www.amazon.com/Fowler-72-641-300-Flex-Indicator-Combo/dp/B000FMQ1TW/ref=sr_1_7?ie=UTF8&qid=1431208437&sr=8-7&keywords=dial+indicator+base , Make ...

Perhaps someone decided to mod the accumulators in the transmission or one is sticking. But more likely bad mount or stuck in sport mode

I put mine on a mount made from some wire in a hole I drilled in one of the blanks behind the wheel on the right. Have both a wideband and boost gauge connected to that gauge, will probably add more sensors to it later.

I would take a look at the crank pos sensor, easy to hit when replacing a transmission. Cam pos sensor connector harness likes to get hard and crack too. When I rebuild mine the MAF was bad and would only allow it to run for about a minute before cutting off.