You need to investigate further because it may not be the CV joints at all!
You have an RSX which is based on the RS2 and therefore you have the front LSD as standard. The 'clunking' you are experiencing could well be the sound of the 2 halves of the diff 'knocking' against each other due to the bolts breaking. I do not know of anyone who has had CV joint problems but I do know of 5 or 6 people who have had this diff problem including myself. Let me dig out the FAQ on it....
Front Helical LSD
Cars affected:
Evo 4-6.5 (possibly other Evo's with the Helical LSD fitted)
Symptom:
A regular 'clunking' noise from the front with a every rotation of the wheel but only on full or partial lock. It will 'clunk' all the time on lock regardless of suspension travel. It can affect the left, right or both sides. The symptom is exactly the same as CV joint wear except inspection of the driveshafts will reveal no joint problems or 'play'. The 'clunk' can also be heard coming from the transfer box if listened to from underneath the car.
Problem and cure:
This is a problem with the factory fitted Front Helical (Torsen) Limited Slip Differential. The Helical LSD is standard fitment on RSII's, optional on the RS and were never meant to be installed on the GSR's however it seems they were fitted to some GSR's when the production line ran out of normal open type diffs.
The 'clunking' noise occurs because the bolts securing the two halves of the diff start to break or come loose. The 'clunk' happens on full or partial lock as that is when the diff is under the most strain. Generally no damage will be caused to the diff unless it is left for a long time before it is repaired.
The cure for this is to replace ALL four of the securing bolts, even if some are not broken, with high grade items.
Note there is very little detail on how to strip the Transfer box and diffs in the workshop manuals. You can find details for stripping the Transfer Box in the installation manual for the upgraded Ralliart front LSD which is available here -
http://www.poweraxel.com/ralliart/catalogue/pdf/instructions/evo6/cp_lsd.pdf . Also note that there are no official services parts other than the oil seals for inside the Transfer box so the bolts will have to be sourced from a fastener supplier (use 12.9 grade M7x25mm bolts with countersunk heads).
Also have a look at this
thread in the Gearbox/Transmission forum for some more pictures.