P0430... NOT the MIL eliminators.

floridaboy said:

So I have a BBK O/R X, with MIL eliminators. I was getting a code P0430- Bank 2 lean condition. I thought it was a bad MIL eliminator or I switched them to opposite banks and cleared the code. I'm still getting the P0430 so I guess it isn't the MIL. Where should I start looking for the problem? Could the O2 sensor be bad? And I though I read somewhere that it may be an exhaust leak. Any suggestions? Thanks a lot for your help.

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P0430 is telling you that the catalyst efficiency is too low on bank 2, not that bank 2 is lean.

A MIL is a low-pass filter. It takes the rear O2 sensor signal, which on a car with an O/R pipe will be moving between rich and lean like the front O2 sensor, and electrically filters it to smooth the signal out. This looks to the PCM like a catalyst doing the its job chemically.

If the O2 sensor is bad -- open circuit, shorted to ground etc -- it may well not respond as expected and the filtered output of the MIL will look wrong to the PCM. I'd start looking at the rear sensor on the driver's side (bank 2).