If so, what are the problems that causes this? Trying to figure out the problem before taking it to the mechanic.
Stock 1991 Honda CRX DX Auto.

Before going into the Emission shop, I had my muffler replace back to stock. Brand new, since it came with some hacked exhaust, which was on the wrong side of the car! Afterward, I drove straight to the e-shop which is like a block away. I guess, I should had warm up the car or something.

During the test when it was on the dyno, I can smell the fumes from the car, kind of strong. Anyways, I fail HC (limit was 1.20 and I got 1.28) and NOx(limite was 2.50 and I got 4.61)

I am thinking about getting a tune-up for the car, or maybe just try to replace the cat converter or something.

Any inputs?

And where is this ignition timing switch and how do I set it?


Modified by ITRex at 5:55 AM 6/8/2008

 

changing the cat fixed my nox.

change your oil, plugs, cap and rotor, wires and that should help your hc. also check your egr.

 

Usually when all the numbers are up points to the cat.

I recommend that you replace the 02 sensor whenever you replace the cat. Just to make sure both are working.

Another thing that would point to the cat is the 02 reading from the test. The numbers should be from 0.3 to 0.0% for a good working cat.

Someone with a 91 chime in for the "service connector" Or you can search for it, there should be a million posts for timing connector


Modified by thesmogman at 8:42 AM 6/9/2008