I'm going to change the TPS on my '01 S40.
Any tips would be appreciated.

 

You are the first person I've ever heard of changing it. What prompted the work?

 

I've got a distinct ruff running at about half throttle, irregardless of RPM.
I've changed plugs and one coil.

 

Turns out it's not that hard to do.
First, I got the P/N from autopartswarehouse
I copied the # and pasted it in Amazon - it's cheaper (just a bit) and I get free shipping - also ordered an oil filter and some non-auto stuff.
Remove the air inlet hose - from the intercooler to the throttle body (tb), looks like a big radiator hose. Shoulda given the clamps a spurt of penetrating oil.
Use pliers to retract the clamps on 2 vac lines between the tb and exh manifold. Then disconnect the hoses.
Loosen / remove 4 tb bolts - a 10mm deep socket came in handy.
Remove the retaining clip from the throttle cable bracket above/behind tb. Lift tb enough to remove the throttle cable from the bracket.
Lift & rotate tb to disconnect the tps wire connector - I hadda look at the new one to know which side of the connector the release tab is on.
Re-installation is pretty straight.
I had to look at the old tps to know the orientation of the wire connector and again for which side the wire connector release tab is on...
I turned on the ignition and pressed the throttle all the way and released it. Ignition off and back on, then started it up.