I would if it has not had one in the last 2/3 years change the CTS, clean the iscv on the throttle housing(there is no airflow metre), check co level.
The tps is easily checked in situ, just identify the signal wire and do a check for any patches or dead spots when you slowly open it, it should be very smooth reading.
You normally find these are missing abit up to about 1/3 throttle as this points wears more than others, as in that position more often, you will have to reset the tps when/if you put a new one on.
tabetha