Emmisions

Well, I have a 1987 xj, and I was wondering if you guys had any suggestions on what I should do as far as getting it to pass emmisions;

I failed the CO; At cruise the limit is 120, and I was at 173; Idle, the limit was 1.0, and I was at 1.16; Any ideas? Any help would be GREATLY appreciated!! Thanks.

Before the test, I usually take a good twenty mile run up the interstate. Check the condition of my plugs and distributor cap. Make sure the motor is hot for the test (the hotter the better, within limits). New air filter!
The 02 sensor and the Cat, deal with CO. The CAT works best when hot.
If you still have the original 02 sensor in there (with the little heat shield) it´s got to be a big question mark.
Same with the original CAT. They say they can go bad anytime after 7 years. I still have my original CAT in my 88, passed the last test barley. The CAT in the 95, had to be changed, for the last test.
A new air filter, often really helps, smooth a motor out.