07jdmfit

i have a 1993 del sol it passed all my smog but the no ( noc) gasses max was 720 i was 745 how can i lower them to pass smog?????? any help would be great

thi3v3z

well the catalytic converter reduces no gases, you best bet would be to buy a new one.

07jdmfit

thanks just found out that cat was replaced a month ago but that spark plugs are old , timing is retarded 10 degrees , and i did not run car for long before smogging it also i think i should have been runnin 91 octane instead of 87

boostedcivicsir

nox is related to high cylinder temps. this is what an egr helps prevent.
make sure timing is dead on.

07jdmfit

the timing was retarded by 10 degrees over stock settings , everything i read says that should have helped i only missed the max by 25 ppm ( 720 was max mine was 745 damn that sucked)

speedracer9k

set timing at 15 degrees, run vehicle for a good amount before you it smogged, and when your there, dont shut off the car. let it run while you wait. you want the cat as hot as possible. timing will help alot.

07jdmfit

thanks