there are additives you can buy that can help to reduce emissions.... redX is one of them..
i had a peugeot 405 some years ago. i was there when they tested the emissions and was shown the print out.
A FAIL ! the guy doing the mot suggested i use an additive. i thought he was trying to rip me off for a couple of � but, like you i needed the car...
i put the stuff in the fuel tank and ran the car around for 5 min. went back to the garage, and got a pass..
not 100% guarentee, but it MAY do the job.
:-)