I recently just failed my emissions test. Readings were,

HC ppm limit- 58 reading- 69
CO% limit-.32 reading-.49
NO ppm limit- 435 reading- 1181

I changed the cat, O2 sensor, new plugs, wires, valve cover gasket and pcv.
I just had a retest and it still failed. Readings were better though.

HC ppm limit- 58 reading- 15
CO% limit-.32 reading-.02
NO ppm limit- 435 reading- 705
The curb idle test passed on both occasions.

So I put the timing light on and it was too advanced by 5 degrees. So I set it right at 15 BTC. Could that be what failed the test.
Thanks
Craven

 

When you set the timing, did you short the connector you use to check engine codes? You need to do that so the computer doesn't adjust the timing while you are adjusting the timing.

High NO levels are typically resolved by cleaning the EGR ports on the intake manifold. I think I mentioned this on your previous post as well.

 

I didn't think the car would start with the connector shorted. I will re time it today. I pulled the egr off and it was pretty clean and operated properly. When I push up on the diaphragm it stalls. For what it takes I might as well put the new egr plugs in too. My car runs smooth as silk with no hesitation, so I'm sure there are no blockages, but who knows. What are your thoughts on seafoaming through the brake booster?

Craven

 

I used seafoam before on my engine. I made a lot of smoke come out of my exhaust, but it didn't really change how the engine runs. If you decide to use it, then make sure you add a little bit at a time. I think adding too much could hydrolock your engine.

The only way to clean the EGR ports is to remove the plugs. My 95 were pretty plugged up and I could get the engine to stall by lifting up the valve. Cleaning the EGR on your car isn't too bad. You have to remove those plugs on the intake. You probably replace them with new ones after you are done cleaning.

 

I just cleaned the egr ports. It was easy to do. There was one port that looked bad, but the rest were partially open. They are all clean now. Hopefully this does the trick.

Thanks.
Craven

 

Hope it does the trick too. Let us know how it turns out.

 

Well I think I robbed Peter to pay Paul. But it passed, barely. My HC, and CO came up but my NO came down just under the limit. Timing and EGR port cleaning must have done the trick. I'm glad it passed, but still not happy with results. Oh well I have 2 years till next test. Thanks again guys for your help.

Craven