Here is some information I located on a PPS site. After applying technique he describes I have not had a single issue with my .40 PPS.
Walther PPS Observations:
I believe that by following these steps, 90 percent of the problems that are associated with this handgun can be aleviated. That's if you are having any problem at all in the first place. I compiled this list based on 7 months ownership of a PPS, 20 years as a "amateur gunsmith", and many hours spent on Walther PPS forums. (Yes, info from people just like you!) This is a great firearm that needs a little extra attention during the break-in period and lubrication of the disconnector. Note: On a Glock this is called a "connector".
1) Very tight, close tolerance handgun. Needs to be properly cleaned and lubed.(Don't all firearms!)
2) Magazine springs are under outrageously high tension. A real thumb buster at first.
a) They do break in after use. I always store mine fully loaded. (no, this does not weaken the spring)
3) High magazine spring tension pushes up on the cartridges so hard that it slows the slide down.
a) During break in, grease (lube) the underside of the slide area that moves across and picks up the cartridges. (Loading ramp)
Don't fully load the magazines for the first 100 or more rounds.
4) Disconnector also induces drag on the slide during forward movement. This is the hesitation you feel in the slide just before it goes into battery.
Disconnector location: Slide removed, located in the handgun frame, against the aft right slide rail.
Nickel or S.S. color. Marked with an "S".
Disconnector function: a safety which prevents the pistol from firing in an out of battery condition.
a) Lube disconnector tang and area of slide that engages/disengages the disconnector. (Disconnector ramp)
The Walther manual doesn't tell you this but lube the disconnector in the area where the trigger bar slides across it. This smooths out the trigger and prevents the trigger from not resetting. This was a problem I had with my PPS. Lubing the disconnector permanently stopped this malfunction. This is a very important step! Don't skip it!
5) If nessessary, polish the feeding ramp and top of chamber. Smooths cartridge feeding function.
6) Find the backstrap size that you like and than don't remove it. It is not nessasary to remove it for cleaning, just make sure the magazine is removed and the chamber is empty, point in a safe direction, than pull the trigger and remove the slide. Wow, just like a Glock!
7) These handguns normally hit low on the target due to the European style of sight picture, Point of Aim verses American style of 6 o'clock position. Don't know the difference? Look it up on the internet.
8) Due to the short, narrow slide (lighter mass) this firearm is susceptible to "limp-wristing". Use a firm grip during trigger pull and follow through.
Hope this helps a few people out that are having issues.