I have a 89 Accord DX (manual) That won't pass smog (California). It passed at the 25mph but not at the 15mph test. I was told it was running lean. Any ideas why it would be doing this and where I should start trouble shooting? The timing and vacuum lines are good. Any help would be appreciated. Thank you.

 

Emissions tests usually detect CO, NOX, and HCs (I thinkt).

Did they tell you which one was out of range?

 

Yes. It was the NO that failed at 15mph.

 

NO emissions can mean that something is up with the EGR.

Hopefully poorman212 will chime in, because I never owned a carbed vehicle.

 

Well I'm not a good smog expert, where I live (the older ones) they just check that the lights work, no visable exh leaks, tires have tread, a few other simple things and say good day....and we don't know how "far off" the car is.

But from my readings, check for exh leaks, "flex" pipe just infront of the converter would be the best place to start. Cold, raise car and start, put you hand all around that flex joint and feel for leaks.

Assume that all tune up stuff is up to date.....any mod's? What is the timing set at?

Next on the list would be the EGR valve, inspect and clean.