I have an 03 Explorer 4.6L that is running bad. The code was P2196, I changed B1S1 O2 sensor and cleared code. A few mins. later the SES light was on, I checked codes and now I have P2196 (again) and P0405. Can anyone give me some insight as to why I was only getting the O2 code and now I have it again after replacing it and a new code (0405 EGR)..
**Any kind of info on this would be great**

 

That code does not mean the sensor is bad, it means you are running rich. So replacing the sensor does not fix the issue. I would look at a bad injector or a ruptured FPR diaphragm (if that year has one), or fuel pressure too high.

The second code does not mean the EGR is malfunctioning, again, the code gives diagnostic clues. It is often the DPFE sensor, at least on earlier years it was. If you are running rich, you get lots of carbon deposits, those deposits could be clogging passages. So you may just need to clean the passages out. Obviously if the rich condition is not corrected, the passages will just plug up again.

 

Thank you for the reply I will look into it more tomorrow. I will update.

 

I'm confused. In another slightly earlier thread you mention that you changed the EGR sensor rather than the O2 sensor. Here you state that you replaced the O2 sensor but make no mention of the EGR.

-Rod

 

Sorry for the confusion, I'm new to this.. I had my wife type the first post for me but after she posted I seen that she said it backwards, so I typed a new one. This it what I have going on: It started running bad so I had the codes pulled, the only code was 2196 (O2 sensor B1S1) the guy at the parts store told me "the EGR is a known problem with the Explorer and the O2 code could be an EGR problem instead". At that point I was not sure what part I should buy, he gave me a print out of probable causes, none of them said anything about the EGR so I bought and replaced the O2 sensor. we cleared the SES then it came back, checked it again and got 2196 and 0405. I don't understand why I'm getting the EGR code after changing the O2 sensor. If it is the EGR why didn't it have that code before and why do I still have the O2 code now? Was he Right, I should have did the EGR not the O2. Today I took the EGR off and cleaned it out, Truck ran great for about an hour and had more power than ever before, THEN it almost died at a stop sign and SES was back on with both codes. I do not know what I should next. I have read many threads and do not see any with the same issue as this one. Again sorry for the confusion.....

 

It's not the EGR valve that is a common issue on these, it's the DPFE as mentioned by Khan above. And the 2003 4.6L Explorer does still use a DPFE. And as you can see from the code definition for the P0405, the code is pointing to the DPFE system (Differential Pressure Feedback EGR). You may also notice that possible causes for the P2196 could be due to the EGR system as well.

Per the factory service manual, below are the possible causes for each of the diagnostic codes you're getting.

P0405-DPF EGR Sensor Circuit Low Voltage Detected

• DPFEGR circuit short to GND
• Damaged DPF EGR sensor
• VREF short to GND
• Damaged PCM

P2196-Lack of HO2S-11 Switch, Sensor Indicates Rich

• Electrical:
  • Short to VPWR in harness or HO2S
  • Water in harness connector
  • Open/Shorted HO2S circuit
  • Corrosion or poor mating terminals and wiring
  • Damaged HO2S
  • Damaged PCM
• Fuel System:
  • Excessive fuel pressure
  • Leaking/contaminated fuel injectors
  • Leaking fuel pressure regulator
  • Low fuel pressure or running out of fuel
  • Vapor recovery system
• Induction System:
  • Air leaks after the MAF
  • Vacuum Leaks
  • PCV system
  • Improperly seated engine oil dipstick
• EGR System:
  • Leaking gasket
  • Stuck EGR valve
  • Leaking diaphragm or EVR
• Base Engine:
  • Oil overfill
  • Cam timing
  • Cylinder compression
  • Exhaust leaks before or near the HO2S(s)

Do you have a scan tool that will allow you to monitor things such as the DPFE voltage in real time? Or a scan tool with a means of backprobing connectors?

-Rod

 

No scan tool... If it is the DPFE is it possible for it to throw 2196 only and
do you have any idea why 0405 showed up after the O2 sensor change?

I think I can get my hands on a scan tool but I'm not sure how to use it for monitoring..

 

I'm not sure if this helps. I noticed that it runs great when the engine is cold, as soon as the temp gauge starts to move it starts to sputter, this happens when at idle and while driving (while driving - it will only do it at slow speeds and take off, if I let off of the gas a reapply, it goes away until the next stop or take off) . I have also noticed that when its sputtering and shaking at idle it has no affect on the RPM's (it stays right below 1000). If I rev it up while in park, when the RPM's come down it runs good for about 2 minutes, then happens again.

 

A scan tool that can monitor various parameters in real time, and knowing which parameters to monitor and what they should show, is probably the best way to diagnose this properly without just throwing parts at the truck. The relationship between the DPFE duty cycle, MAF rate, O2 voltages, ECT reading, TPS voltage and manifold vacuum could help determine what the likely issue is.

I suppose it's possible that the old O2 sensor was slow enough to respond to changes in the exhaust oxygen level that the ECM wasn't noticing the relationship to the EGR operation, but that's totally speculation.

Maybe the place for you to start now is to confirm the vacuum hoses connected to the DPFE are in good shape and connected, then make sure all the other vacuum hoses are good and you don't have an intake manifold leak (not all that common on the 4.6L).

I know in 2004 the Explorer had an electronic throttle by wire but I'm not sure if the 2003 has that. That might effect if you have a TPS voltage showing on the scan tool.

-Rod

 

I had the scan tool ran and this is what he wrote down:

ERG - 0% (closed) while running and not running
MAF - voltage 1.01 gm/s 6.70
he also wrote gm/s 5.85 & 0.94 volts
DPFE - 0.14 with a jump up to 0.15 every now and then.
IAC - 54%
EGRVR - 0%
EVAPCD - 0%
CYL - 1-8 No Fault (0)
-----------------------------------------------------
O2 Sensor activity:
TEST #1 TEST#2
B1S1- 1500 w/ 1251m/v 1157
B1S2- 0 w/ .09m/v 64
B2S1- 800 w/ 745m/v 101
B2S2- 820 w/ 784m/v 809
*ENGINE OFF (after running for 30 min.)
B1S1- 1665
B1S2- 70
B2S1- 45
B2S2- 74
-------------------------
*There was a side note the said: "at idle B1S2 would jump from 0 to 20 while sputtering.
*There was a side note the said: " after engine off B1S1 dropped MUCH slower than the rest.
----------------------
I'm not sure what all this means.
***WITH THIS INFO, CAN SOMEONE TELL ME WHERE THE PROBLEM MIGHT BE?

 

Assuming "ERG" was supposed to be "EGR" then 0% at idle and engine off makes sense. The EGR valve should be closed at idle since it would be a vacuum leak if not closed.

An IAC of 54% seems quite high. It sounds like the IAC is opening trying to keep the engine from stalling.

The readings shows for B1S1 appear to be bogus. A standard O2 sensor such as what your Explorer has should never read above 1V (or 1000 mV). I do seem to recall reading somewhere about an issue that causes scan tools to read bogus O2 sensor data on some of the earlier OBD2 Fords but I wouldn't expect your 2003 to have an issue. Also, if it was effected this way, I would expect it to cause the B2S1 reading to appear bogus as well.

Did you get a Universal fit O2 sensor that you needed to wire up or did you get an OEM sensor by application?

-Rod

 

It was an OEM sensor. does the info lead back to the O2 sensor? The guy that did the live data for me put my truck in the air and looked at bank 1 on both sides, he told me that he thinks my uncle may have put the new sensor on the wrong side, he showed me where they plug in and the one on the driver side was a white and the other three were green, the sensor on the driver side looked cleaner than the others also.

 

I think you mean he looked at Sensor 1 on both sides. There is only one Bank 1. On your generation of Explorer, Bank 1 would be the passenger side. So if your uncle put the new sensor on the driver's side before the catalytic converter, that was in deed not B1S1, that was B2S1.

-Rod

 

Ok Thank you. I will get another O2 sensor and get it put in the right place. I will let you know what happens.

 

You could try disconnecting the B1S1 sensor and then see what reading you get on the scan tool to confirm you don't have a wiring issue.

-Rod