My '99 SVT 50k miles had seemed a little sluggish for a while and then 402 came up. I ignored it for a while, but based on this board decided to replace the DPFE with the plastic one from Autozone. What a difference !!!!! Smoother idle and LOADS more kick when I step on the gas - it just wants to go faster. I was thinking of selling the car - now it's just like new. Thanks for the advice.
BTW it takes all of 30 minutes to do. ( And I did it on a hot engine !) You can't even ( easily ) mess up the hose connections as they are different sizes.