Hi Scotty,

I have been watching your videos now for several years.  Thanks for the information…I use your tips and try to follow your advice on cars.

I purchased a used 2004 Toyota Camry XLE, 2.4l 4 cylinder engine, from a friend whose husband passed away.  It was her husband’s car.  I purchased the car six months ago with 129k miles, and it now has about 134k miles.

when I purchased the car I would get an intermittent check engine light.  The fault code showed a bad oxygen sensor on bank 1.  After speaking with my mechanic, we agreed to replace the sensor with a Denso (OEM) sensor.  My mechanic replaced the sensor, but then got a fault code showing the other oxygen sensor was bad. We replaced that sensor as well with a new Denso sensor.

Now the check engine light stays on all the time.  The autozone scanner still shows a bad oxygen sensor.  I put a Bosch one in (to verify that the Denso sensor was not the issue) and the code remained, so I returned the Bosch sensor and replaced it back with the Denso sensor.  I believe the Denso O2 sensors are ok.

I have also cleaned the mass airflow sensor, replaced the ground wire on the battery, and cleaned the throttle.  Nothing seems to get the check engine light to turn off.

the car runs great, with no issues.  I would like your opinion on next steps:

1) leave it alone and resign myself to the check engine light being on.

2) my mechanic recommended taking the car to a Toyota dealer.  He thinks the PCM is not getting the correct voltage, and believes the dealer, with a high level scan tool, can reprogram the PCM.  My mechanic does not have a scan tool like that.

Thanks in advance for your expertise.  I am in NW Ohio, otherwise I’d drive the car to you directly.

best,
Pat