un-plug the air flow meter when the engine is running and then check the pcm has set a code for it.

KOEO and clear the codes

all the codes should now be gone.

if the DPF has a ash restriction Regenerating it will not work, if its just soot it will work.

any thing over 4 psi of back pressure you can not do a static or dynamic regen .

( 101 kpa = 14.7 psi )

you will need to have the DPF properley cleaned,

new after market ones are junk fit one at your own perril,

i find the only way is to clean a factory item or fit a new one,

spray DPF cleaners as far as i know will not remove ASH

what ever option you choose tell the computer you have fitted a new DPF

should be JOB DONE.