Aloha: Check Engine Codes O2...

[DaBoss]

Aloha folks,

The past couple of weeks I've noticed when engine is warmer, been running and I come to slower speeds I hear a clicking noise or something from the engine compartment. I've seen my rpm gauge quickly fluctuate at lower rpm's or sputter. Finally last Friday the Check engine light came on, when my mechanic checked the codes, this is what came up: PO135, 141, 155, 161 and 443.

My mechanic checked all 4 of the original O2 sensors and said they were fine including the heaters that are part of them. So, he reset everything, drove it for a while over the weekend and the light didn't come on. Started well, purred.

Today I heard the clicking noise for a moment and the engine at low rpm sputtered. Check Engine light hasn't come on yet.

Question: is all of this only related to the 4 O2 sensors and wire harness connection or could something else be going on? Again all 4 02 sensors are original and vehicle has 175K on it, 4.0L V6. Can all sensors start to go out at the same time? If I have to replace the sensors should I go with the Ford Motocraft ones.

Look forward to all advice and if something else could be happening. Mahalo

 

[DaBoss]

In addition to the O2 sensors x4, mine are the originals with 175k on them, when typically do fuel injectors in these engines go out? I did replace one about 2yrs ago.

Look forward to the advice in regard to O2 sensors, wire harness if needed, other parts that may need to be replaced. Mahalo!

 

[DILLARD000]

OxSensors wear out & need renewal along with IgnitionPlugs+Wires every 100kMiles\12Years.
As their ChemicalReactiveElement fades away, they slowly push the Air/FuelRatio to the rich end of the curve,
causing lower MPGs & the exhaust to run rich & the CatCons to run hotter, eventually causing a much more expensive repair.

A Bosch 15719 with 24i00 0m610 Long Cable+Plug is good to replace any Ford 4WireNarrowBand Sensor.
Use CableTies to route+secure the harness for GroundClearance & away from HotExhaust+MovingParts.

 

[Todd Z]

Gen 2?
Pull the battery and tray, Under the tray is a harness that the battery acid drips on to and eats the wiring. Start there.
I only use AGM batteries because of this crappy ford design.

 

[DaBoss]

OxSensors wear out & need renewal along with IgnitionPlugs+Wires every 100kMiles\12Years.
As their ChemicalReactiveElement fades away, they slowly push the Air/FuelRatio to the rich end of the curve,
causing lower MPGs & the exhaust to run rich & the CatCons to run hotter, eventually causing a much more expensive repair.

A Bosch 15719 with 24i00 0m610 Long Cable+Plug is good to replace any Ford 4WireNarrowBand Sensor.
Use CableTies to route+secure the harness for GroundClearance & away from HotExhaust+MovingParts.
View attachment 4504

Aloha Dillard, thank you as always. I'm assuming that my O2 sensors are original and thus need to be replaced. I've always tried to get Ford Motocraft parts but am curious about the Bosch sensors as many on Rock Auto like them as well. They are also half the price. Have you had good luck with them? These are the two Bosch sensors that Rock Auto show for my 2007 4.0. Mahalo!

Bosch 15664 upstream, Bosch 15717 downstream

 

[DaBoss]

Gen 2?
Pull the battery and tray, Under the tray is a harness that the battery acid drips on to and eats the wiring. Start there.
I only use AGM batteries because of this crappy ford design.

Aloha Todd, yes it's a Gen 2, 2007 4.0L.

I will definitely check under the battery tray as well as to look into the AGM batteries! BTW can failing O2 sensors affect performance, like at low rpm, engine sputtering? I had this symptom before the Check Engine light came on previously. Doesn't happen often but I notice when engine is warm/hot. All my fuel injectors are original but one. So just wondering if these Oxygen sensors affect how the engine runs. Thank you again! Mahalo!

 

[DILLARD000]

...assuming that my O2 sensors are original and thus need to be replaced
...always tried to get Ford Motocraft parts...curious about the Bosch sensors...half the price
...Have you had good luck with them?
...Rock Auto show for my 2007 4.0...Bosch 15664 upstream, Bosch 15717 downstream

Bosch is the original maker+supplier of OxSensors to Ford factories,
so buying Bosch is simply eliminating the middleman & price markup.
Note all FordMotorCraft 4WireNarrowBand OxSensors are the same SensingTip+thread, same 4WirePinout, same Plug; only difference is the 4WireCable length.
The Bosch 15719 has the longest available cable, thus will work to replace all Ford 4WireNarrowBand OxSensors,
& allows alternate routing for GroundClearance & away from HotExhaust+MovingParts; use CableTies to route+secure the cable and tuck\fold away any extra length. Life would be simpler if Ford+PartStores only stocked one length.
As always, it's your vehicle & money, so choose what makes you happy.

 

[DaBoss]

Bosch is the original maker+supplier of OxSensors to Ford factories,
so buying Bosch is simply eliminating the middleman & price markup.
Note all FordMotorCraft 4WireNarrowBand OxSensors are the same SensingTip+thread, same 4WirePinout, same Plug; only difference is the 4WireCable length.
The Bosch 15719 has the longest available cable, thus will work to replace all Ford 4WireNarrowBand OxSensors,
& allows alternate routing for GroundClearance & away from HotExhaust+MovingParts; use CableTies to route+secure the cable and tuck\fold away any extra length. Life would be simpler if Ford+PartStores only stocked one length.
As always, it's your vehicle & money, so choose what makes you happy.

Aloha Dillard000, thank you so much for explaining that! I was wondering if the oxygen sensors were the same, minus the length! And thank you about the history, I read where it said Bosch is the original. I'll get 4 of them!

By the way can a failing O2 sensor affect the running of the engine, sputter every once in a while? Take care now. Mahalo!

 

[DILLARD000]

When engine first starts and OxSensors are cold,, computer runs engine "open loop" on a preprogrammed fuel/air ratio, ignoring the OxSensor signals. Once OxSensors are hot (forget at what minimum temp, typically 2~3min after start) computer runs engine "closed loop", using the 2 upstream OxSensor signals thru an equation that constantly adjusts the fuel/air ratio for a balance of economy+performance+emissions. DownStream OxSensors are used only to monitor CatCons+Emissions & set a TroubleCode if out of spec.

An intermittent engine sputter could be caused by any of several things going bad: OxSensor \ IgnitionPlug \ IginitionWire \ IgnitionCoilPack \ FuelInjector \ FuelPump \ IACValve \ ThrottlePosSensor \ MAFSensor \ CrankShaftSensor \ CamShaftSensor \... A broken\bare wire or cracked\leaking vacuum hose\gasket are also possibilities.
I'd try these remedies in the order listed:
* Bottle of FuelSystemCleaner & PremiumGas Fillup & new Oil+Filter: needed every 4kMiles\6mths
* New AirFilter: needed every 8kMiles\1Yrs depending on weather & driving conditions.
* Clean MAFSensor & ThrottleBody & IntakeManifold & IACValve & PCVValve, new FuelFilter, inspect Wiring+Plugs & VacuumHoses+Fittings: needed every 33kMiles\4Yrs
* New IgnitionPlugs+Wires+OxSensors+PCVValve, be sure Plugs are gapped proper, Clean+OhmCheck CoilPack: needed every 100kMiles\12Yrs

 

[DAM Sport Trac]

Aloha folks,

The past couple of weeks I've noticed when engine is warmer, been running and I come to slower speeds I hear a clicking noise or something from the engine compartment. I've seen my rpm gauge quickly fluctuate at lower rpm's or sputter. Finally last Friday the Check engine light came on, when my mechanic checked the codes, this is what came up: PO135, 141, 155, 161 and 443.

My mechanic checked all 4 of the original O2 sensors and said they were fine including the heaters that are part of them. So, he reset everything, drove it for a while over the weekend and the light didn't come on. Started well, purred.

Today I heard the clicking noise for a moment and the engine at low rpm sputtered. Check Engine light hasn't come on yet.

Question: is all of this only related to the 4 O2 sensors and wire harness connection or could something else be going on? Again all 4 02 sensors are original and vehicle has 175K on it, 4.0L V6. Can all sensors start to go out at the same time? If I have to replace the sensors should I go with the Ford Motocraft ones.

Look forward to all advice and if something else could be happening. Mahalo

My response is based on the assertion that aforementioned mechanic has verified the 12v reference (koeo) at each O2 heater circuit wire and that the wires are good and not melted to the exhaust.
Having that many codes at once all dealing with the same system (emissions controls) is screaming electrical/ecu issue. First place I would look is the multi wire harness connector near the throttle body for damage. Heat and age can cause the wire insulation to deteriorate and allow for a short to ground which can also result in damaging circuits in the computer. Also check the ecu/pcm connections for water or poor connection.
The code to address first is the P0135.

My gut/experience is telling me that the ecu/pcm is the issue but always verify poor harness connection and wiring damage first.

 

[DaBoss]

My response is based on the assertion that aforementioned mechanic has verified the 12v reference (koeo) at each O2 heater circuit wire and that the wires are good and not melted to the exhaust.
Having that many codes at once all dealing with the same system (emissions controls) is screaming electrical/ecu issue. First place I would look is the multi wire harness connector near the throttle body for damage. Heat and age can cause the wire insulation to deteriorate and allow for a short to ground which can also result in damaging circuits in the computer. Also check the ecu/pcm connections for water or poor connection.
The code to address first is the P0135.

My gut/experience is telling me that the ecu/pcm is the issue but always verify poor harness connection and wiring damage first.

Aloha DAM, thank you very much for your reply. My mechanic was wondering why all the codes came up at once.

I will ask him to check the wiring, wire harness. If damaged, can these be ordered, individually replaced or does one have to "splice" in new connections?

Also, even though my 02 sensors maybe okay, with 175k on my truck, would you go ahead and replace them? Thank you again. Mahalo!

 

[DaBoss]

https://www.summitracing.com/parts/mof-wpt152
BTW I found this above O2 sensor connector, would this work for all 4 of my oxygen sensors? Mahalo and thank you very much!

 

[DILLARD000]

https://www.summitracing.com/parts/mof-wpt152
BTW I found this above O2 sensor connector, would this work for all 4 of my oxygen sensors? Mahalo and thank you very much!

If your problem is a melted chassis harness or socket, then that connector would be needed.
Need to crawl underneath & put a good eyeball on those cables & connections,
before buying parts that you may not need.

 

[DaBoss]

My response is based on the assertion that aforementioned mechanic has verified the 12v reference (koeo) at each O2 heater circuit wire and that the wires are good and not melted to the exhaust.
Having that many codes at once all dealing with the same system (emissions controls) is screaming electrical/ecu issue. First place I would look is the multi wire harness connector near the throttle body for damage. Heat and age can cause the wire insulation to deteriorate and allow for a short to ground which can also result in damaging circuits in the computer. Also check the ecu/pcm connections for water or poor connection.
The code to address first is the P0135.

My gut/experience is telling me that the ecu/pcm is the issue but always verify poor harness connection and wiring damage first.

Aloha Dam and Dillard, my mechanic went under my vehicle, it sounds like the wires are okay. He believes my PCM needs to be reprogrammed at the dealer, they charge $220 for this service.

Question: does the PCM from time to time need to be reprogrammed? I realize mine is now 16yrs old. Would this fix the issues and possibly load any updates? Would you caution me not to do this? Lastly does this PCM mainly control the Mass Air Flow sensor, Oxygen sensors and so forth?

Thank you for all your help. Mahalo!

 

[DaBoss]

If your problem is a melted chassis harness or socket, then that connector would be needed.
Need to crawl underneath & put a good eyeball on those cables & connections,
before buying parts that you may not need.

Aloha Dillard, and on the way home the Check Engine light came on, lol! It's okay. My mechanic will pull the codes tomorrow, I will let you all know what is going on and double check the wiring. Mahalo!

 

[DaBoss]

If your problem is a melted chassis harness or socket, then that connector would be needed.
Need to crawl underneath & put a good eyeball on those cables & connections,
before buying parts that you may not need.

https://store.allcomputerresources....a-12a650-bpa-pcm-ecm-ecu-engine-computer.html
Aloha Dillard and DAM, if it's is my PCM engine computer, is it better to go to the dealer and get my original one reprogrammed or smarter to go with one like in the web link above? I noticed prices are between $299-399. Any suppliers you'd recommend?

Thanks again for all your information and help. Mahalo!

 

[DaBoss]

My response is based on the assertion that aforementioned mechanic has verified the 12v reference (koeo) at each O2 heater circuit wire and that the wires are good and not melted to the exhaust.
Having that many codes at once all dealing with the same system (emissions controls) is screaming electrical/ecu issue. First place I would look is the multi wire harness connector near the throttle body for damage. Heat and age can cause the wire insulation to deteriorate and allow for a short to ground which can also result in damaging circuits in the computer. Also check the ecu/pcm connections for water or poor connection.
The code to address first is the P0135.

My gut/experience is telling me that the ecu/pcm is the issue but always verify poor harness connection and wiring damage first.

Aloha DAM & Dillard, okay my mechanic pulled these codes off today: PO 135, 141, 155, 161.

He showed me my wiring and connectors, they all look good, not melted, stained with an liquid. The wiring harness to the PCM looks good too.

He used to work at Ford and said the issue with getting a rebuilt PCM is that Ford will have to program it and the keys, he doesn't have the capacity to do it.

Question: should I get the rebuilt PCM or should I just go to the dealer and let them reprogram my current one, hoping it's a software issue?

Thank you again! Mahalo!
PS: my mechanic did ohm tests on all the oxygen sensors and they were within specs, all quite a bit below the mark of I forgot 12 or 15. He showed me when he reset/cleared the codes, if it were any oxygen sensors, upon start up the check engine light should come right back on, it didn't. So he suspects the PCM.

 

[DaBoss]

My response is based on the assertion that aforementioned mechanic has verified the 12v reference (koeo) at each O2 heater circuit wire and that the wires are good and not melted to the exhaust.
Having that many codes at once all dealing with the same system (emissions controls) is screaming electrical/ecu issue. First place I would look is the multi wire harness connector near the throttle body for damage. Heat and age can cause the wire insulation to deteriorate and allow for a short to ground which can also result in damaging circuits in the computer. Also check the ecu/pcm connections for water or poor connection.
The code to address first is the P0135.

My gut/experience is telling me that the ecu/pcm is the issue but always verify poor harness connection and wiring damage first.

Aloha Dam, Dillard, Todd Z,

want to thank you all for your help! By going through all the areas you folks recommended, my mechanic and I could dial in on specific areas to look. My mech used to be a master mech at Ford til the dealership dropped the line and only kept Subaru, so he was happy I could receive your advice. He tested all the heaters on my sensors multiple times, the readings in ohms where always in the range for both the upstream and downstream sensors. He reset my engine codes multiple times, always the same codes.

My mechanic suspected the PCM ECU then I saw Dam's reply. I then put this in a new thread about and sure enough, Nick responded about his experience with a customer of theirs, sounded like my issue. He said where the PCM is located, there is a lot of heat generated right there. So he suggested to his customer to find a good used PCM that had the same model number on the outside of the box, they flashed it and reprogrammed the keys and remotes, works well again. Nick actually painted his PCM with a heat shield type of paint and added an additional grounding wire, which I will be doing too.

I found a good used PCM, cleaned the outside with steel wool, wiped all the dust off and found a Ford dealership that works on a lot of trucks willing to do this for me. I went in last Friday, explained the situation, they swapped out my original PCM with the nice used one, flashed it, programmed the keys and wow, so far so good!

I may try to have my original PCM rebuilt and flashed so it is ready to go if needed. Thank you all for your help! One of the techs at this Ford service said to me, so often it is the PCM and people don't want to try what I did, as it could be very easy but it takes a bit to coordinate and best to have the dealership do the flash and swap. Mahalo!