Reading the previous posts, you had a P0420. What work/troubleshooting has been done since your last post? Is P0141 the only code remaining?

The shop manual I have might have an error on the pin 4 wire color to the secondary O2 sensor connector. One page says blk/red and the other says blk/yel. What are the wire colors on the engine side of that connector using the picture below? Your car is similiar to my TSX, where my TSX has that connector under the passenger seat. Your 06 accord may have the same setup.

 

yes, my car has the connector at the same location. Since the last correspondence, I did the upstream O2 and the the MAP. The car is a rocket, I don’t know what could be wrong with this thing lol
I will check the connector tomorrow evening when I get home from work. Tonight I’ll be late.

 

Thank you!!

 

Unplugging the connector and putting a test light across pins 3 and 4 should caues the light to turn on when you turn the key to the II position (or try to start the car). You'll need to find out if the sensor has an open in the sensor, or the harness side is not getting power or ground. A volt meter would also be a good first check on this circuit, then hook up a test light across pins 3 and 4 to see if the circuit can send enough current to turn on a test light.

Here is a video on an open in the sensor side that you can also try on the sensor side of pins 3 and 4. The resistance should be 6-10 ohms on a normal circuit.

 

Alrighty.. I checked it out more tonight. I have enclosed a little legend of what my colors are at this connector- see attachment. That said, I used my test light and got a bright light across pins 1 & 4. There is Green wire with a black tracer for position 1 which was the supply power; Position 4 is the Black wire with red tracer. See more text below the enclosed attachment. Thanks a lot!

there was only incoming power from #1; nothing from the others, or between them. Ground issue?

 

As PAhonda stated hook up the test light between terminal no. 3 and 4 of the unplugged harness connector. Turn the ignition switch to the ON position (car not running). Does the test light illuminated?

 

I appreciate your reply. I absolutely did EXACTLY that and got no reading. As stated in my last reply, I DID get illumination between pins 1 and 4. ”1” being a green wire with black tracer & “4” being the black wire with red tracer.

 

That would indicate possibly an issue either with an open (break) in the Blk/wht wire that goes terminal no. 3 of the secondary O2 sensor harness or an issue with PCM.

If you have something that can test continuity, you can unplug Connector E (terminal no. 21) at the PCM and test Blk/Wht wire for continuity to try to rule out the wire being the cause.

 

I didn't catch the pin 3 to pin 4 test in your last post either, but you are getting close to figuing out the issue. From now on, you don't need to test pins 1 and 2 as they are good. Pin 4 is also good and you don't need to test, because you have power. The issue you are facing is Pin #3 has no ground.

You either have a broken blk/wht wire somewhere between pin 3 of the connector under the passenger seat and the PCM, C551 along the way has a poor connection, or the PCM is damaged electrically and can't supply ground.

Here is a quick way to narrow down the issue based on the picture below. Plug in the O2 sensor connector under the passenger seat. Find C551. If you have the shop manual I recommended earlier, #17 on page 22-35 is C551 and also #6 on page 22-43 is the other half of C551. To add further complexity C551 will be a 4 pin connnector if you car does not have XM Radio and/or does not have navigation. C551 will have 17 pins if you have either XM or navigation or both. Disconnect C551 and look for corrosion/damage on the pins. Find the blk/wht wire on the bottom halfof the connector that comes from the floor. Hopefully you only have one blk/wht wire to the connector. If not, do not test and let us know. We can figure out which is the proper blk/wht wire to test. Hook up your test light to a bare metal bolt for a good ground. Touch the blk/wht pin on C551 with the key in the II position.

If the testl lights up (it may be dimmer as you have a load from the O2 sensor heater coil), then the purple wire is good in the picture below. If it doesn't light up, then the blk/wht wire is broken somewhere between below the passenger seat and that connector.

My reply is a bit long, but we are trying to test the purple section of the blk/wht wire in the diagram below. Depending on your results, we will give you suggestions for the red highlighted section.

 

Connector C551 is on the right kick panel area: