1992 Toyota pickup smog check with pass and fail on two different smog tests.

It passed Idle Emission Tests, but did not pass EGR (functional) and Ignition Timing was defective. i had Ignition timing fixed and took it to a second Gold Station (it was right next door).

It passed all tests except the HC (PPM) test, which passed at the first Station. Inconsistencies at the two stations include: Station 1 used GVWR of 5999 lbs and on the Idle Emission Test Results used M1: 0 mph, where the HC (PPM) passed at 18. Station 2 used GVWR of 8499 lbs, and on the Idle Emission Test Results used M1: 15 MPH where the HC (PPM) failed at 116, although it passed on M2: 25 MPH at 75.

I understand the first failure due to the defective Ignition timing, but why did it pass the HC test the first time and not the second time? And now what should I do? Thank you for your help.

Answer:		Assuming your 1992 Toyota pickup's ignition timing was "retarded" prior to the second smog inspection, the repair involved "advancing" your Toyota's timing. With the ignition timing corrected your Toyota should not produce be high HC. It appears the repaired timing problem has uncovered further high HC problems. posted by SmogTips Support