I recently changed the Bank 1 Sensor 1 Oxygen Sensor on my 1997 Toyota Avalon, which has about 40,000 miles. I applied the anti-seize lubricant that came with the Denso 234-4622 O2 Sensor.
The MIL went off after 14 miles, but the car failed the Calif. NO test as follows: 15 mph - 889, 25 mph - 1183. The rest of the scores were very good, very low. I then drove it 140 highway miles. Turned off the DTC code in memory. Drove it another 70 miles around town with little NO improvement on a retest as follows: 15 mph – 852, 25 mph - 1139.
There are no other DTCs except that for some reason (?) the “EVA” cycle has not yet run.
Questions:
1. Could excess anti-seize lubricant squeezed out, and sitting in the airflow stream raise NO?
2. Could the “EVA” failure to cycle be a clue as to what might be going on?
3. If not 1 and 2 what else might be the problem?
4. What if anything can I do to correct the problem, whether excess anti-seize or your other thoughts? For instance, if it’s possibly excess carbon buildup, is there an additive that I might add to clean that out?
