Just thought I'd share this information to someone who may need it in the future. car failed ca smog due to high numbers in NO (PPM) I cleaned egr valve checked All vacuum lines and cleaned egr pipe to no avail though egr pipe and valve were due for a cleaning anyhow. Anyways checked the EGR MODULATOR by sucking on the bottom and it held no vacuum the diaphragm was mangled used one from my friends sc400 ran it to the smog shop and passed easily. Just thought I'd share and here are the numbers might have to tilt your head because of the way I took the photo thanks club lex - davisk

 

Common problem