P0051 Nissan -

Question

My 2003 Nissan Frontier SE Crew Cab 3.3L Automatic (none supercharged) suddenly developed a problem. When I parked it at night it was fine. Next morning it would not run properly.

The code showing on my Innova 3160b scanner reads:

P0051 Generic
Ho2s Heater Control Circuit Low
(Bank 2, Sensor)

Then the CAT, EVA, and EGR are flashing. Not sure if that means anything or not.

I have replaced all spark plugs, new plug wires, new rotor, new cap. Replace fuel filter and all air filters.

Electrically check the MAF (working perfectly) and cleaned it with proper cleaning spray.

Replaced two upstream o2 sensors.

New gas cap.

Checked battery and cleaned posts.

I plan on replacing both downstream o2 sensors, but as of yet, have not done so.

Can you give any other suggestions?

Answer 1

first thing to do was check the wiring and if its fine, replace the sensor. Worst case scenario the ECM might be bad

 

the possible causes are:

-Harness or connectors (The heated oxygen sensor 1 heater circuit is

open or shorted.)

-Heater oxygen sensor 1 heater

 

Comments

Finally am able to get back to my original question I had asked.....I did replace the two downstream o2 sensors.  Cleared the code of p0051 and started my Nissan Frontier 2003.  For about one minute, it ran normally, then suddenly the dreaded "service engine soon" (ses) light came on.  At that moment, it seems to have a very slight "miss" or hesitation when I accelerated the engine.  It can not be wet as it has been parked inside for almost 3 months now.  I wiggled all the wires and gave a slight tug on each one, then a slight push back into each other.  All was firm and connected snug.  Someone told me that it may be a fuse or a fusible link that may be no good.  I pulled and continuity tested each fuse and they all turned out good.  Since I am not exactly sure where the correct fuse or fusible link is located in my fuse box (one under the left side of dash, the other in engine bay on R.H. (pass) side, under a lid).   Does anyone know exactly which fuse or link it could be?