My 97 had its first cel 7/08 at 140k mi. Autozone scanned and showed a PO773. Figuring it was not affecting emission, cleared code before emissions test and passed testing. Did the same before '09 test- same Autozone, same PO773, same testing station. Cleared code, passed test. Of course, the cel remained on ater 2-3 trips, until I had to disconnect battery for one reason or another. This year, no visit to Autozone to confirm code, just cleared cel before test. However, this time went to different test station. Test conducted differently from other station- they shut car off 2x (don't recall previous test shutting car off). Had no cel before test. Avy failed test. Test showed P1410 and cel was on after test. Went straight to Autozone with cel on. Readout showed only PO773 code. Next day, not knowing which, if either, code was correct, replaced the EGR sensor and added can of SeaFoam Trans. Treatment to tranny. Drove enough to let SeaFoam work, drained and refilled tranny, then cleared cel. Made 5-6 trips- NO cel. Back to emission station that failed avy, retested, PASSED with no codes. Is it possible (1) Autozone's scan tool read the wrong code both times, or (2) just a coincidence that, shortly before or during this year's test, avy got a 1410, but SeaFoam treatment had cured the 773, or (3) the original test station did not pick up the 1410 or 773 (if needed to pass emissions) because they didn't conduct the test correctly. Your guesses?