[juan1407]

My 1991 integra wont pass emissions. the NOx level is too high. im trying to get it fixed and dont really know where to start. i was first told the egr valve come to find out my car never had one. now i am told the PCV valve which i cant seem to find. when i start the car it idles at 1400rpm. but as i drive it for a bit it goes to normal 600-800rpm. its a B18A1. all stock.

 

[Mac8008]

nox levels increase when exhaust temperature increase. The first thing to do when you fail for this is to check your static timing. You probably could advance it to the upper limit of factory specs.

Increased exhaust gas temp are also a sign of increased engine wear. As you rack up miles, the exhaust valve seats get worn and don't seal their best which increased the temps. You may wan't to consider getting a leakdown test to check the status of your engine

 

[juan1407]

ok. im new to all of this and dont know that much but am trying to learn. how do i check the static timing? and exactly which seals should i replace or chek into?

 

[Mac8008]

static timing = timing when engine is idleing at a specific rpm usually 750 You need to get a timing light to check the timing.

I didn't say anything about seals. I said exhuast seats may be not sealing 100%. I suggest you get a leakdown if you static timing is proved to be in spec.

Perhaps get a manual or find someone that can help you do these things

 

[juan1407]

i have a few people that are willing to help me figure things out. thanks.