1999 Toyota Camry LE 3.0l Ignition Timing
 

My car failed SMOG check because of this code P0420. They are a few possible causes, but one of them I believe is the improper ignition timing. Above the camshaft, it has four timing marks: 15, 10, 5, 0 and the pointer mark points to10. But I used my timing light to check to see how it points to and it points to 15, not 10 (the pointer mark). So I tried to locate the distributor to adjust it to the pointer mark, but I could not find the distributor. Please help me locate the distributor or it does not have one. Thank you very much.

There is no distributor. The ign system uses cam and crank position sensors for timing plus the engine computer.

P0420 is typically the emissions converter. A decent ODB scanner would be able to view the AF sensor voltage outputs to determine if the converter is not working.