I have a 2001 Jaguar Stype and i recently took my car to the mechanics to have the suspension changed. Once i turned on my car the sign saying CATS System fault appeared,what might be causing that to appear?

What kind of noise you are hearing exactly?

the cylinder numbers are confusing early engines are rh bank (lh as you look from front) 1357, lh bank 2468, later engines rh bank 1234 lh bank 5678 at your year it could be either way round.

the adaptive damping system, adcm. is linked to the abs system. it controles the valves in the shock absorbers to make the suspension hard or soft and i think it adaptes to how you drive. you should take your car to someone with suitable diagnostic equipment to get the fault codes out of the system, the problem is more than likely one of the shock absorbers. the system defaults to hard suspension when a fault is present and puts that warning on. hope that is helpfull.

42 dollars, 31 for front go on autopartswarehouse.com

You may need a shop to look at this.
Code 420 is saying the catalytic converter is not working well on bank one and code 430 is the same thing for bank two.
There is an O2 sensor in front and behind each cat. The computer uses the readings from the front and back sensors to judge the performance of the catalytic converters.
Since it would be very rare for both cats to fail at the same time, chances are the problem is a vac leak or injector problems with the engine. I would say something wrong is happening before the exhaust gets to the catalytic converters.

On both rear windows, or just one? If its just one then probably the regulator mechanism in the door has broken (there are some rather fragile plastic parts that can snap with age). The mechanism is easily replaced by removing the door trim (take out two screws found under the rubber mat in the door handle well, and pry off the whole door panel with a wide blade screwdriver or cats paw (start at top edge nearest to rear - 4-6 snap fittings should pop off reasonably easily). Unscrew old mechainsm and replace the whole thing.. Parts usually available on Ebay for $50 to $100, make sure you get the correct orientation, front and rear, and left and right, are all different parts - Lincon LS parts also fit perfectly).

If both windows not working and stopped at the same time... sounds electrical.. start checking fuses?

This sounds like a alarm problem, try closing and locking your door, then using your remote to unlock as if you have just got to your car in the morning... Im thinking along the lines that you car alarm is activating the ignition auto shut off....

I have exactly the same problem on mine-you explained perfectly,i was told i need to change the cruise control computer.I recently had the thermostat changed and the mechanic wiped the engine sign off that was triggered by the cruise control not available sign coming on-when he did this it took about a month for the problem to recur so i think the probelm is definately electrical not mechanical or it would have happened straight after he wiped the engine sensor light.could be air mass sensor could be cruise control computer-when i get some money i'll get it done

http://consumerguideauto.howstuffworks.com/2000-to-2002-jaguar-s-type.htm

http://www.motortrend.com/roadtests/sedans/112_0207_2000_jaguar_s_type/index.html

http://www.carsurvey.org/reviews/jaguar/s-type/r117992/

these are some reviews on the car... if you need any other information on it let me know. i won't mind if you send me one too hahahaha.

Robert

WATER CONTROL VALVE.LOCATED AT BOTTOM OF RADIATOR ON DRIVERS SIDE.HAS 5 WATER PIPES COMING OFF IT.CHANGED MINE YESTERDAY AT A COST OF £145 +VAT.HEATER IS NOW RED HOT