AUDI 1999. REPLACE A LOWER CONTROL ARM. VALET DONE ON THE CAR. IMMEDIATELY AFTER REPLACING THE CONTROL ARM THE CAR STARTED MISFIRING AND DOES NOT WANT TO GO. ANY SUGGESTIONS. THANKS PIERRE

In order to replace the right front lower control arm you will a spring compressor. That's the most important tool you will need so that the spring does not fly out at you when you lower down the control arm. The control arm bolts are 21mm or 22mm nuts & bolts depending on if alignment adjust bolts installed or not. If adjustment bolts are installed then you will want to pay attention and note to which side the notches face so that you install them back into their original position. The ball joint nut will either be a 17mm or a 19mm. 16mm for the shock and a 22mm & 17mm for the sway bar link. Compressing that spring is the most important part of the jb though so don't forget to compress it.

sometimes it can end up cheaper replacing the whole lower control arm rather than just the bushing due to the labor/time it takes to remove and replace just the bushing get a second opinion to be sure

i would replace it, not easily done you need special tools

Are they all on the turn signal arm

The lower ball joint is not replaceable, if the ball joint is defective the lower control arm or transverse link must be replace

the shocker will self adjust, dependant on load in/on car.(trailer etc)
just take off and replace as is.

put a jack stand under the ball joint lower car, this applies pressure on the ball joint so the shaft of the ball joint does not turn.
heat the nut as well.

comes as lower control arm assmbly

It's good to shop around for new tires, the mechanic may not have a good deal from the supplier. Therefore, he needs to charge more. Just shop around in your area for better deals on tires.

As for the other repairs, the first thing you'll need to get done is the front lower control arm ( the worn ball joint ). Worn out suspension parts will cause premature wear on the tires. Because, it would not be holding the tire steady and it would be basically " out of alignment ".
If I remember correctly, the whole control arm would have to be replaced, because the ball joint isn't changeable in the control arm. I believe that's why he's asking $700.
The mechanic again probably doesn't have a good deal on his parts supplier. I think it's too high myself. I would call around other shop for better prices. Other shops that have better deals on their suppliers will usually pass the saving to the customer.

replace the speed idle sensor