Upon inspection in the state of Tx. my 94 Del Sol did not pass due to high nox gases. What can be done to bring done to bring nox down to a passing status? I recently rebuilt the top end and changed the timing belt. This car has 156.000 miles and runs great. There is no EGR system so I need help in getting this problem fixed ir she has to stay parked.

Thanks to who ever can help!

 

retard the timing a few degrees. NOX is cause by combustion temps being too hot either caused by running slightly lean or timing being too far advanced. I had this problem with my 90 Integra and this helped. Also some states can do an off the roller test which doesn't check for nox. At least it doesn't in MD. might wanna run some injector cleaner too.