I have a 2000 4Runner with 31000 miles. I took it to a smog check and passed. However, some of the readings of the result are higher than average particularly in the HC testing ( what is HC?)
Here's the reading:
15 MPH test 25 MPH test HC (PPM) HC (PPM) Max: 49 Max: 32 Avg: 8 Avg: 6 MEAS: 47 (amt measured) MEAS: 12CO (%) CO (%) Max: 0.62 Max: 0.75 Avg: 0.02 Avg: 0.02 MEAS: 0.06 (amt measured) MEAS: 0.01
NO (PPM) NO (PPM) Max: 501 Max: 754 Avg: 88 Avg: 82 MEAS: 159 (amt measured) MEAS: 17
On the 15 MPH test I barely passed the HC and reading for NO is higher than the avg. The smog guy said I might need a tune-up. Another factor could be my engine wasn't warm enough during the testing.
Any idea what causing the high reading and how I should improve it? Thanks.