hello i recently just got an sc300 5 speed a month ago and im having trouble getting it to pass smog.
Test #1 my first test went ok i just didnt pass NO at 25mph it was way off and was told to change the egr valve




Test #2 month later changed the egr valve and went in for a retest today. NO didnt pass at 15mph and 25 mph NO barely passed. also the HC was higher than the first test barely passed as well. Guy said said timing was off too.




i would like your guys input on this, would timing be the last thing i need to fix? also why did the HC go up?


please help
thank you

 

I feel your pain bro. If I were batting in the smog league, Id be at about a .200 average! I just passed smog on my SC400 fter I failed 2 days ago. I originally scored HC 39/19 (73/56 max allowed) CO .02/.00 (.49/.39) NO 614/590 (530/487) so I failed NOx by a slim margin. Guy hinted it may be a plugged EGR so I went home and removed it off the side of the intake (V8) and looked at it. It was so plugged that I couldnt even tell it had 2 holes, the one on the bottom was clear, the one on top was just a smooth black inlay with a little stump coming OUT of it that interfaced with the intake holes. So I started chipping the black out and found out the the top hole was actually a trough with a hole at the bottom. I cleaned it down to metal and also cleaned the seat and pintle. I went back today with NO OTHER modifications and rolled the dice. I passed...barely, The NOx levels went down to 299/314 (roughly 50% of old test), but my CO went up .05/.06 and my HC just squeaked by at 72/44, 73 was max allowed. I dont know how the other results went UP with no other mods. car has at same temp for both tests at a 5 mile drive to smog place. Next time Im going to run 25% acetone....but maybe my injectors will be cleaner then, as the car had sat 6 months prior to me putting 1500 miles on it in 17 hours. Thank goodness I didnt have to clean out the EGR pipe at the back of the intake. That would take a while to pull.