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

Forum > Failed Smog Test > Question

1993 Ford Ranger failing NO(PPM) at 15mph only.

My 1993 Ford Ranger recently failed smog due to a high NO (PPM) at 15 MPH. The specs are: (15 MPH) NO (PPM): MAX: 533, AVE: 136, I tested: 815 (25 MPH) NO (PPM): MAX: 786, AVE: 124, I tested: 631 My CO is: 15 MPH: MAX: 0.70, AVE: 0.06, I tested: 0.04 25 MPH: MAX: 0.84, AVE: 0.05, I tested: 0.02 I am fairly certain that I simply need to clean my EGR system. The valve itself works, however, a vaccuum tester gauge does NOT change rpm or idle speed, which leads me to believe that the EGR lines are clogged. Any other ideas? I passed the rest of the test just fine.
Answer:

We think you're right on the money. Disassemble the EGR, we're certain you will find the exhaust and intake passages to and from your Ford Ranger's EGR valve clogged. With some carburetor cleaner and a metal flexible rod clean the passages both on the engine and the EGR valve, reinstall the EGR valve and expect to see a decrease in idle when vacuum is applied to the EGR valve with your vacuum hand pump. 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