engine hose replacement

[Ed]

I am aware of the lower elbow hose below the lower intake manifold that needs to be replaced from time to time. Basically if this little 90 degree hose leaks too much air, it will pop your O2 sensors. This little hose you can hear hissing by standing on the drivers side as close to the fire wall as possible. If it is hissing its time to replace, FYI, it may not hiss until the engine is at normal temp. With that said, I am now hearing a hissing sound more prominent than the other hose on the PAX side about the center of the intake manifold. Is there another common hose here thats needs to be replaced? Are there any other common vacuum lines that should be periodically changed out? I have a 2001 Jag S-Type 3.0. Great car, 30 + MPG using AMSOIL.
Lastly, I just upgraded my lights to HID lightening, WOW! However, when I took the light assembly out, I found out that both assemblies were completely falling apart inside, so there is now way I can adjust the beams. Had to hard set them. Looking for replacements, new ones on line run from 400+ -600. Any recommendations here? Also looking for cold air intake and adding rear shelf speakers.

[Neil]

Yeah front light adjustments are made from plastic and they tend to break
I would suggest checking out Ebay for much better price on using lights BUT make sure they are OK. If you see a stype with front damage most likely adjustment plastic parts are broke so do not bid on these.
Remember that you need headlamps made for US so do not bid and order from let's say Germany.

From my own experience if your headlamps can't be adjusted up/down, then it can be usually fixed (glued or even a new small part made from aluminium if you have proper tools), if horizontal adjustment is not working - the part is a bit more complex and usually it can't be glued because there is a screw going thru it.

Make sure the color/wear matches your cars other headlamp. It was a bit strange for the looks when car's left side headlamp was much clearer than left side........ (this is why you can't order just one BRAND new headlamp...and you need get a used one if you are having problems with just one headlamp).