hello to all,I've changed the fuel filter & module on my 99 regal 3.8 LS,it still stalls out when riding down the hwy. could a fouling plug cause this ? Am I getting ready to go broke trying to fix what I just bought 4 months ago?

Welcome to AF.

Your post has been moved to it's own thread. We prefer that posts concerning Regal models after '97 are not shared with earlier models prior to '97.

A common problem for unexplained stalling may be the crank position sensor (CKPS) if the fuel pressure is within specs. A fouled spark plug will typically cause a misfire condition not stalling. Normally the SES/CEL light will blink or illuminate and a DTC code may be stored. On CKPS problems the SES/CEL light may not turn on.