EFI Gurus, I need your help! EFI Trouble Diagnosis

[luderchris]

Well... I can't switch the o2 sensors from side to side because the connector on the passenger side has been repaired and uses a weather pack connector.

Since I last checked in I so checked/set the TPS and it is at 0.96. Good to go there.

 

[luderchris]

So I just ran the KOEO and KOER codes again. Getting KOEO of 31,81,82,85,84 and KOER of 12,13,41,91,31.
Still getting the o2 sensor codes.
I ran the codes 3 times and was also getting C code 14 (PIP sensor) until I cleared the codes and ran a 3rd time, the 14 did not come back.

 

[chuzie]

If u cant swap the o2 connectors u have no choice but to hook up breakout box and verify the harness also run sensor procedure to eliminate o2 sensors themselves. You really have no other options.

 

[luderchris]

Ok. I'm going through this procedure--

http://www.stangnet.com/mustang-forums/threads/help-me-create-the-surging-idle-checklist.698148/

I did the IAB test and I get 12v at the red wire, but when I probe the red and light blue (instead of to ground) I only get 0.74, and it doesn't go any higher. It says that means terr is a short to ground on the lt blue wire. I can't get a test light to light up as they describe either = bad connection between wire and IAB.

 

[luderchris]

Breakout box now hooked up. Stay tuned...

 

[luderchris]

On the wire diagram, I interpret hego L as driver side and hego R as passenger side. Is that correct???

 

[chuzie]

Correct....

 

[luderchris]

Then I think we just found one of the issues. The o2 sensors are on the wrong sides. Because the connectors are different, I need to switch the sensors themselves.
Stay tuned...

 

[luderchris]

Ok. Looks like 7/8 wrench. Found one but to big/wrong angle to get to the sensor. I'll pick up an O2 sensor wrench tomorrow.

 

[chuzie]

If it incorrect wiring in harness, swapping sensors positions will accomplish nothing. Now, if you have one bad sensor and one good sensor, then swapping will be useful.

If I understand you correctly, it sounds like you need to swap harness positions.

 

[luderchris]

If it incorrect wiring in harness, swapping sensors positions will accomplish nothing. Now, if you have one bad sensor and one good sensor, then swapping will be useful.

If I understand you correctly, it sounds like you need to swap harness positions.

I have the wiring running to the wrong sides. Currently, I have pin 43 wire running to the passenger side, it should go to the driver side (and vice versa). Because one side wiring has a different connector to the sensor than the other due to a previous repair of a melted connector (sitting on header), I can't just leave the sensors and switch the wiring, I need to move the sensor that has the correct wiring, the wiring will follow the sensor, and pin 43 will go to the driver side where it needs to be (and vice versa for the passenger side).

Does that make sense?

 

[chuzie]

Gotcha. Makes sense. U r on the right track.

Fwiw- at some point u may want to consider purchasing a replacement plug for the harness. Otherwise you will have a hell of a time replacing that sensor on the road if need be.

 

[luderchris]

Gotcha. Makes sense. U r on the right track.

Fwiw- at some point u may want to consider purchasing a replacement plug for the harness. Otherwise you will have a hell of a time replacing that sensor on the road if need be.

That is a good point. Thanks.

 

[luderchris]

Ok. I ended up leaving the sensors and just switching the pins in the harness at the computer.

No change. Same issues, same codes, including the 41 and 91 o2 sensor codes.

 

[chuzie]

If your pins were switched that may be part of the issue. Did you run the procedure for testing the actual sensors?

 

[luderchris]

Not yet. Still need to get a tool to pull out the sensors.

 

[chuzie]

Read that post again. The process requires them to be installed and vehicle running.

 

[Sporto]

We fixed it today. Was a bad TFI module on dissy.

Took awhile but we got it!


Rich

 

[chuzie]

So this could have been solved at post #28. Ouch. Glad you got over there and fixed it. Good job.

 

[luderchris]

So this could have been solved at post #28. Ouch. Glad you got over there and fixed it. Good job.

I did replace the TFI at post #34, and was able to get the truck started, but apparently the replacement TFI was bad too! A third TFI module did the trick. Purring like a kitty now.

I drove the truck about 25 miles today and all is well so far with the engine/EFI. Still need to button up a few things, but it is well on its way to getting back on the trails, and inspected so it is legally on the street.

Thank you all for your help.

Chris