emolina
Active Member
- Joined
- December 24, 2000
- Messages
- 51
- Reaction score
- 0
- City, State
- Los Angeles, CA
- Year, Model & Trim Level
- '97 XLT SOHC
1997 4.0 SOHC with 114,390 miles. Almost failed smog due to high HC. Here are the results.
At idle (RPM=689): %CO2=14.6, %O2=0.4, HC=92, %CO=0.32
At RPM=2377: %CO2=14.6, %O2=.5, HC=35, %CO=0.25
Replaced spark plugs and wires 2 years and 9,000 miles ago. O2 sensor replaced 2 years ago when it threw a code. Cleaned the MAF two days before the test.
What might be the cause of the high HC?
Thanks for your help.
At idle (RPM=689): %CO2=14.6, %O2=0.4, HC=92, %CO=0.32
At RPM=2377: %CO2=14.6, %O2=.5, HC=35, %CO=0.25
Replaced spark plugs and wires 2 years and 9,000 miles ago. O2 sensor replaced 2 years ago when it threw a code. Cleaned the MAF two days before the test.
What might be the cause of the high HC?
Thanks for your help.