I am suspicious of my throttle position sensor, as sometimes the engine is very jerky coming off and on the throttle, it's almost like an on/off switch at times. No fault codes stored, but that doesn't mean it isn't faulty!

I was thinking the easy way to find out is to simply swap the throttle bodies from another car, and see if that changes anything (since the TPS is integrated). Scrapped 2.5s are plentiful compared to 3.0s so can I fit 2.5 throttle bodies and expect the car to drive well? I'm not bothered about losing top end performance as it will only be for a test -- I can spend more time trying to find 3.0 throttle bodies if this turns out to be the problem.

Alternatively, can the TPS itself be swapped over easily, and if so are 2.5 and 3.0 sensors the same?

Cheers.

Cable adjustment is fine, there is a tiny bit of slack in it when closed, just enough to confirm that the throttle is sitting against its stop rather than being held by the cable. Likewise with the cruise cable.

Can the TPS be removed easily with the throttle bodies still bolted to the car? That may be an easier option than swapping the lot. I'll check the part numbers when I get home but I see no reason for the 2.5 and 3.0 to be different.