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Mike V.
Mike V., Nissan Technician
Category: Nissan
Satisfied Customers: 25314
Experience:  Nissan factory trained and Certified Subaru Technician.
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I am not a mechanic. I am just doing homework before I go to

Customer Question

Hi Mike. I am not a mechanic. I am just doing homework before I go to the mechanic. I have a 2003 Nissan Sentra GXE 1.8L. A few days ago I was driving and lost throttle power. I found myself cruising at almost 10-15 miles an hour. Just a month earlier, my mechanic changed the alternator since it did almost the same thing. I thought maybe the alternator went bad. I cruised to the nearest auto-part store had them check the alternator and found out it was fine.
I turned off the car and started it and to my surprise it ran fine. Today I drove to another auto-part store and had them check the "engine light on"; it is always on. My car has 165,000 but well taken care of. The person checked with code scanner and came out with P0605 & P0420. I know there was a problem with the catalytic convertor, we don't have emissions control annual check in my state. Can you give me your opinion please?
Submitted: 1 year ago.
Category: Nissan
Expert:  Mike V. replied 1 year ago.


The code P0605 is the one that caused the car to go into fail safe mode. This is why you didn't have any throttle response and it would only go 15 mph. The P0420 is a faulty catalytic code, but at this time I would be much more concerned with the computer issue. This is a tough code to diagnose only because it's possible the computer lost power and the computer itself is not the problem. This really needs to be tested with the dealer scan tool, but I suspect you will need to put a new computer in the car to resolve the issue completely. It is not a common issue but it does happen time to time.

Please let me know if there is any more I can do to help you from here.

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