My Toyota 4runner 2007 model came up with the following error codes after scanning and it consumes a lot of fuel.

  1. po606 - ECM/PCM processor
  2. po158 - 02 sensor circuit high voltage bank 2 sensor 2
  3. po332 - knock sensor 2 circuit low bank 2
  4. po500 - vehicle speed sensor A
  • Kindly assist me with pictures of the bad parts as well
    – user49471
    Commented Jun 3, 2019 at 23:59

1 Answer 1


The first code you list (P0606) is a general code indicating a failure in the Engine Control Unit (ECU) itself - specifically the Engine Control Module/Powertrain Control Module (ECM/PCM) processor. This means essentially that the ECU has detected an internal malfunction with that processor, in most cases a code indicating an ECU failure means you can pretty much no longer trust any other codes that get thrown - if the ECU itself can't trust what values its seeing then neither can you.

Now that would be bad news - ECU's are seriously expensive bits of kit and you don't really have much choice but to brace yourself (and your bank account) and go to the main dealer. There may be a hail mary in this case though - 4 Runners of this era have occasionally been known to throw this code spuriously when there is a problem with the O2 sensors, it's not common but given the presence of O2 sensor codes (and the accompanying poor fuel consumption) it's worth a shot in my opinion to try replacing both the bank 2 O2 sensor and the rear O2 sensor in the exhaust and try clearing the codes. It's a gamble but if it solves it the a couple of O2 sensors is a hell of a lot cheaper than replacing the ECM.

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