Join the community and post your question. Use our Ask-A-Tech for free now! ASE experts standing by.

Forum > Failed Smog Test > Question

1992 Jeep Cherokee Sport..failed the NO. Max limit was 711, mine was 722.

Just wondering what you think the problem could be. Failed the NO (ppm.. max lvl should b 711 and my Jeep Cherokee hit 722. The SUV has 204,000 miles and oil isn't to bad. Water is in the coolant container instead of coolant and it's not the cleanest. Also don't no much about the catalytic converter but I don't believe it's bad. What can I do to get it to pass that extra 11 points?
Answer:

Your 1992 Jeep Cherokee is not equipped with an EGR valve or EGR system. Normally the EGR valve (Exhaust Gas Recirculation) system controls and lowers NOx. On your Jeep Cherokee, NO is controlled completely by the air/fuel mixture and the Catalytic Converter (CAT). Assuming your 1992 Jeep Cherokee's air/fuel mixture is ok (this should be indicated by normal CO emissions - check your VIR report) we'd recommend suspecting the CAT. If the CAT is the problem the only thing you can do to get your Jeep Cherokee lower NO by 11 ppm and to pass the smog check is the get the CAT replaced. You can find an aftermarket CAT from a muffler repair shop or smog check repair center for a low price. To check the condition of your Jeep's Catalytic Converter a smog check repair station will have to perform a CAT intrusive test. They will need to take an exhaust sample from before the CAT and after the CAT, and compare the results. They will then find out if in fact your Cherokee's CAT is damaged and needs to be changed. posted by SmogTips Support

Related questions and answers you might find useful:

How Do I Get a Smog Check Waiver? by Margaret

Do I Need a Smog Check This Year? by Joy

Mini Cooper DMV Registration Due in 5 Day Won't Pass Smog by anne

2001 Jeep Grand Cherokee Laredo with K&N Air Filter by David

1995 BMW M3 Gross Polluter High HC & NO @ 15MPH by Jared

View SmogTips.com in: Desktop / Mobile