weird skip?

[tylerb826]

i gotta 97 mazda b2300, 2.3L 5speed. Its gotta lotta miles on it 198,000+, and these a hard miles but it hasnt gave up yet. Hasnt had a tune up in three years lol. But after a day of muddin it started actin up the next mornin. When im cruisin down the road its starts jumping and bucking, jus something weird. But when i give it gas it quits or if i let off it quits, it only does it when im jus barely giving it any throttle, u know jus cruising. It idles jus fine and hasnt had any loss of power besides tryin to pull them 33s. Any ideas?

[Earl43P]

Pull the vacuum line off of the EGR valve and drive it like that.
See if the bucking quits.
Replace the DPFE if that works.