It may be caused by the O2 that you suspect is bad....Have you tried to change the sensors around yet? Left to right, clear the codes and see if them come back.
A quick check on
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Your OBD-II Trouble Codes Repair Site P0605 - Internal Control Module Read Only Memory (ROM) Error OBD-II DTC Technical Description Internal Control Module Read Only Memory (ROM) Error What does that mean? This trouble code basically means that the PCM/ECM (powertrain/engine control module) has detected an internal control module fault in the ROM (read only memory) in the PCM. The PCM is basically the vehicle's "electronic brain" that controls functions such as fuel injection, ignition, etc. When self-checks fail in the ROM, this DTC is set. This code is a generic powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may be slightly different depending on the model. A cursory search on the 'net shows this DTC to be more commonly found in Ford and Nissan vehicles. Symptoms Symptoms of a P0605 DTC will include MIL (malfunction indicator lamp) illumination, although there may be other symptoms including but not limited to various warning lights on dash, stalling, and no start conditions. Potential Causes There is an internal fault in the PCM / ECM Using an aftermarket performance programmer may trigger this code Possible Solutions In some cases, "flashing" the PCM with an updated software can fix this DTC. You will need acess to make & model specific information such as Technical Service Bulletins (TSBs). If there are no PCM flash updates, the next step would be to check some wiring. Inspect and check for proper voltage and ground to the PCM and throughout the associated circuits. If there are problems with them, repair and retest. If the wiring checks out OK, the next step is to replace the PCM, which is the most likely repair for this code. This is generally not a "do-it-yourself" task, although in some cases it may be. We strongly recommend you have a qualified repair shop / technician do the work, one that has the capability to reprogram the new PCM. Installing the new PCM may involve using special tools to program the vehicle's VIN (vehicle identification number) and/or anti-theft information (PATS, etc.). As an alternative to replacing the PCM, some specialized shops may actually be able to repair the PCM. That may involve removing the PCM, shipping it off to them for repair, and re-installing it. That's not always an option for daily drivers. NOTE: This repair may be covered under the emissions warranty so be sure to check with your dealer as this may be covered beyond the bumper-to-bumper or powertrain warranty period. Other PCM DTC codes: P0600, P0601, P0602, P0603, P0604, P0606, P0607, P0608, P0609, P0610. Register now to ask a question (free) Related P0605 DTC Discussions Code P0605 History / California DMV Smog Check RE: VW Cabrio 2002 I had a prior "Check Engine" light event with the following codes: P0605 P0103 These were cleared and were fine for 9 months until... I had an immobilizer issue (keys needed to be adopted) after I installed an aftermarket radio (Disconnected battery to install). K... * Need more help with a p0605 code? If you still need help regarding the P0605 trouble code, please post your question in our FREE car repair forums. Share NOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected. If you want to share this article or information with others, please link to this page, don't copy and paste it elsewhere. © 2004-2014 OBD-Codes.com
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