QuestionQUESTION: My check engine light came on after getting error code P0240. My mechanic friend said I needed a Bank one oxygen sensor. He replaced the sensor with Bosch OEM part 13733 and installed it right in front of the engine. A simple part to replace. He reset the code and a day or 2 later the CE light came back on. After researching on-line I am not sure if I replaced the right sensor or put the part in the right place. Should the bank one sensor be installed under the car near the catalytic converter or on the right side of the engine? This all started when I replaced the catalytic converter with a Bosch OEM part # 099-5701. Last year I failed inspection because the car was too loud. The next day after replacing the cat conv, I got a sticker. the next day after that the CE light came on. I'm due for inspection in March and my mechanic friend is no longer around. Been driving with CE light on for 1 year, but car is running fine. The car has 92,000, in the last year haven,t been driving much about 3,000 miles. Previously replaced evap vaccum a couple of years ago at 65 or 70,000 miles. If you can help me I would appreciate it. Thanks. Also, I am worried using the Bosch Oem Cat Converter to save money instead of A factory Toyota Cat Conv was the right move.
ANSWER: Is this a 4cylinder or V-6 engine?
---------- FOLLOW-UP ----------
QUESTION: 4 Cylinder 2.2 L 2364 CC L4 5.Dan, I read other problems about code P0240 on your website and I can assure you the flex pipe which is connected to the Cat Converter was rusted out and needed to be replaced. I still have the original O2 sensor I replaced. So if I installed the new sensor in the wrong place, I can switch them around.Like I said this all started when the Cat Conv was replaced. Thanks.
ANSWER: The bank 1 sensor one is located in the exhaust manifold near the radiator in the front,by the way, I think you mean dtc p0420 which is a cat converter failure code, the converter that causes this code to set is the one that is part of the exhaust manifold, the other cat further downstream is a sub cat which almost never causes this code, the main cat converter, as far as I know is only available from the toyota dealer.
---------- FOLLOW-UP ----------
QUESTION: Question: So , I replaced the right O2 sensor right in front on the exhaust manifold beyond the radiator.I just didn't word it the right way in my first descripton. That's where I replaced it, But it was a NAPA replacement part and I should have went to the dealer to purchase the O2 sensor. This isn't the first time that NAPA Auto Parts gave me the wrong part. But the part fit like a glove. You think a Toyota factory Bank One O2 Sensor will be the solution?
AnswerYou can try an OEM O2 sensor but I don't think it's the solution, in most cases the cat converter causes this code, an O2 sensor of air/fuel ratio sensor malfunction would give a different trouble code, the 420 is usually specific to an inefficient cat converter.
