Volvo Repair: Trouble Codes and Suspension, 2000 volvo s70, ball joints

Question
2000 Volvo S70 GLT SE 2.4L Turbo FWD Auto
65,000mi

-The car has a somewhat poor service record.  Oil has been changed every 3K miles to Mobil1 Synthetic and OEM filters.  Trans fluid was recently flushed. Always had premium fuel.  That is about it.

    About 2 months or so ago my volvo's check engine light turned on while driving on the highway, and then a week later it shut off, and 2 days after that it came on again.  The service soon light is also on, but i think that is on because i have been doing my own oil changes and i have not reset the ECU after doing so.  It runs and drives just fine, so I neglected the problem until I got a letter from the state regarding emissions testing.  Now i have to fix the problem or I will not pass emissions.  I scanned the ECU and came up with 2 DTCs - P1174 and P7100.  The P1174 seems to be specific to BMW cars and it has to do with fuel trim, and on other cars it is related to the cam sensor.  This confused me so i decided ask before i spend money on a new cam sensor.  The P7100 was completely foreign to the scan tool and it did not offer any suggestions.

    My second question is about the current state of my volvo's suspension.  The car has been driven around downtown chicago since it was new so it has never seen a smooth piece of pavement in it's life.  The suspension is getting noisy, and its becomming loose and less comfortable.  I need to know what suspension components i would have to replace to give it that like-new stiffness and ride comfort.  I have not looked very hard for parts, but i did find a couple online stores that sell bushings, ball joints, and other suspension components.  Bushings are cheap, and i would expect the ball joints to be as well, but i have not found a single site that sells them separate from the control arm - everyone sells them with control arms and that makes them very pricy.  I would imagine that only the ball joint and bushing would need to be replaced because the control arm looks like a solid piece of metal that should not wear out easily, afterall, isn't the purpose of bushings to keep parts like the control arms from wearing out? I called the dealer about the prices of some basic components that i know will be needed for the rebuild, but the quote was more than 3 times that of online prices for the same part and brand. Could you give me a list of everything i will need to overhaul my suspension (front and rear)?

Thanks,
-Konrad

Answer
I am not familiar with the generic codes that come from non volvo scan tools and have no way to cross reference the codes.

common suspension problems would be bad sway bar link rods and bad upper strut mount bushings.as for the ball joints they do come built into the control arm and are not replaceable.

the best thing to do would be have the dealer check and diagnose the codes and have them check the suspension and get a list of what is needed.then if you wish you could do the work yourself.

Rege