russiankid
08-13-2009, 12:48 PM
My 89' LX passes emissions but NOx is extremely high. It is at 3592 with a limit of 3600. I did some searching and read that the EGR valve is most likely the cause. So I checked the valve and it holds vacuum. I put vacuum onto the line for the EGR valve, which is line 16, it does not hold vacuum. Looking at the diagram of the black box, lines 16,19, and 3 are all connected together. Line 19 holds vacuum, but it is also connected to a one way valve so the one way valve in the black box works. I then put vacuum onto number 3 and it does not hold vacuum. Line number 16 and 3 are T offed into the main valve and that one way valve(line number 19). I checked the main valve for the EGR system for line number 16 and it holds vacuum. I cannot find any area's in the hoses where they could leak.
I also checked the vacuum at the EGR valve when the car is running and its at zero. Revving the engine does not make any difference.
Any ideas on whats going on here? Car idles nearly perfect, but it does have a small pop noise in the exhaust which leads me to believe there is a vacuum leak. On a good note, the car does pass emissions basically without an EGR.:rockon:
I also checked the vacuum at the EGR valve when the car is running and its at zero. Revving the engine does not make any difference.
Any ideas on whats going on here? Car idles nearly perfect, but it does have a small pop noise in the exhaust which leads me to believe there is a vacuum leak. On a good note, the car does pass emissions basically without an EGR.:rockon: