I though Seafoam was used to clean the system out before replacing the ATF. Will it have any affect on the ATF in the reservoir already ? Will that need to be changed after I add the SF ?

I have a power steering mystery that I can't seem to solve. The steering goes from normal power assisted to heavy and sluggish at random times, and then goes back to normal. I can be driving along at 40 mph and feel the steering start to get heavy, then within 2-3 minutes, its as if there's no more ...

Yes, cleaning the ETM (the new version) will make all of the difference in the world. Those carbon and varnish deposits on the butterfly valve dramatically affect the cars performance. A good cleaning will almost eliminate idle and hesitation problems.

I had a similar problem with my 2001 S80, which has 120K, and a new version ETM. The idle was hunting between 7-10 RPM, and then dropping every 2-3 minutes down below 500, causing the engine to shudder, and almost stall. I had a new ETM installed in 2004 after the previous one went into limp home mo...