I got this car and got it smogged on Saturday, but on Sunday afternoon my check engine light came on. I took it to a shop and they ran a diagnostic and told me I had a bad EGR system. However with a bit of research it doesn't seem possible to pass smog with a bad EGR valve. Maybe it's just dirty or maybe it's something else? It starts up a little rough but idles and drives well, but I did notice a lack of power at low speeds on a cold engine on Monday.
Is it possible to pass a California Smog test with a bad EGR valve? on 1994 Volvo 960
by NateofDressage in Rosamond, CA on February 15, 2012
ANSWER by mastertech6371 , February 15, 2012
may have passed yesterday and the egr failed today. anything can happen. just think, if you had your smog test tomorrow, it would have failed. if you dont believe them, get a second opinion. Roy