Engine code P0420

[kjk]

Read and cleared engine code P0420. I drove it for a few days and the engine symbol is back on my dash. I have not read the code today, but feels like a P0420. Ideas 2007 Expedition EL

[slc10844]

Why do you say it "feels" like a P0420? The code is for B1 catalyic converter. There a quite a few possible causes.

[kjk]

I should say I think it is the same code.

There are a few possibilities and I am hoping to narrow it down if possible. Is it an O2 sensor or has someone had other troubles after getting this code?


Kevin

[slc10844]

Unless you have a scanner that can monitor the O2 sensors, I would replace the sensors. The ECM monitors front and rear sensors, and compares readings to determine if the converter is doing its job. Does the vehicle have, or ever had, a misfire problem? If not repaired quickly, the converter can be damaged and cause a cat efficiency problem that may not show up for some time

[kjk]

No scanner to monitor, no misfire problems.

Is this O2 sensor just behind the drivers side exhaust manifold?

[slc10844]

B1 is the passenger side. The heated sensor is between the exhaust manifold and in front of the catalyic converter.