Car bucking and lacking power

Tiny
MUSTANGS197
  • MEMBER
  • 2007 FORD MUSTANG
  • 4.0L
  • V6
  • 2WD
  • MANUAL
  • 183,500 MILES
Recently I had a check engine light for for bank 2 sensor 2. I replaced the o2 sensor and the check engine light still came back. The car is still bucking, lacking power and will not accelerate very quickly after about thirty minutes of driving. I plan on replacing the fuel filter being that I have had bad gas several times. Other then that I do not know what to look for.
Monday, October 29th, 2018 AT 4:30 PM

5 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Hi and thanks for using 2CarPros.com.

Can you provide the code you had? Also, read through this link to see if there is anything in it that helps. It discusses common reasons for engine surging/bucking.

Let me know if that helps and what the code is you keep getting.

https://www.2carpros.com/articles/engine-surges

Take care,
Joe
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Monday, October 29th, 2018 AT 6:19 PM
Tiny
MUSTANGS197
  • MEMBER
  • 5 POSTS
It is giving me code p0155. At this point I have replaced both upstream and downstream O2 sensors on bank 2. I have cleaned the intake filter and checked spark plugs and cleared the code. But the code still comes back and still starts bucking and lacks performance to the point where it starts cutting off throttle if I try to go anymore then half throttle. Keep in mind the car starts acting like this after about thirty minutes of normal driving. When I start the car and let it warm up it drives fine I can go full throttle no issue for those first thirty minutes of driving.
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Wednesday, October 31st, 2018 AT 8:35 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Welcome back.

I am going to start with the basics. First, under the hood locate the power distribution box. Open it and remove and replace fuse 47 (15 amp) even if it looks good. It may be losing connection when it gets hot. Next, when the fuse is out, inspect the terminals in the box. Make sure they are clean and not pushed or damaged in any way.

Do this and let me know what happens.

Joe
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Wednesday, October 31st, 2018 AT 7:40 PM
Tiny
MUSTANGS197
  • MEMBER
  • 5 POSTS
I have replaced and inspected the fuse terminal and there has not been any difference in the way the car behaves. I have provided a short video so you can hear how the car acts and see how it bucks and struggles to pick up speed in any gear. I went half throttle and held it at half throttle.
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Saturday, November 3rd, 2018 AT 9:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Wow! That ia a problem. I have to ask, is the exhaust system modified?

Here is what I suggest, read through these tests. I eliminated ones that weren't relevant, however, the testing is extensive unless you get lucky and find the issue at the start. These are pinpoint testing procedures. I started at DW9. Pay attention when you get to DW11, which is related to modified exhaust systems. I had to attach all related pictures. It would not let me just ad them. Everywhere you see the word "image" there was a picture. I kept them in order the way the manual had them listed and the way they would follow the test.

DW9 DTCS P0135, P0139, P0141, P0147, P0155, P0159 OR P0161: CHECK FOR A SOURCE OF POTENTIAL HO2S CONTAMINATION

- Investigate the following items as potential sources of HO2S contamination:
- use of unapproved silicon sealers
- fuel contaminated by silicon additives
- excessive oil consumption
- glycol leaking internally in the engine
- lead-contaminated fuel
- short drive cycles in cold weather
- use of unapproved cleaning agents
Is a concern present?
Yes

- REPAIR the source of the contamination.

- CHANGE the engine oil and oil filter.

- RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Resetting The Keep Alive Memory (KAM).

- REPEAT the self-test.

No

- GO to DW10.

DW10 VISUALLY INSPECT THE HO2S HARNESS

- PCM connector connected.

- Visually inspect the HO2S harness for exposed wiring, water contamination, corrosion, and proper assembly.
Is a concern present?
Yes

- REPAIR as necessary.

- Clear the PCM DTCs. REPEAT the self-test.

No

- For DTCs P0139 or P0159, GO to DW11.

- For all others, GO to DW12.

DW11 CHECK THE EXHAUST SYSTEM FOR LEAKS AND MODIFICATIONS

- Check for leaks in the exhaust system.

- Visually inspect the vehicle for aftermarket accessories and performance modifications.
Is a concern present?
Yes

- REPAIR as necessary.

- Clear the PCM DTCs. REPEAT the self-test.

No

- GO to DW25.

DW12 CHECK THE HO2S AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS

Note:Verify the harness pins are in the proper location.

- Measure the resistance between:

image

Are the resistances less than 5 ohms?
Yes

- GO to DW13.

No

- REPAIR as necessary.

- Clear the PCM DTCs. REPEAT the self-test.

DW13 CARRY OUT THE KOEO ON DEMAND SELF-TEST

- Ignition ON, engine OFF.

- Carry out the PCM KOEO self-test.
Are DTCs P0135, P0141, P0147, P0155 or P0161 present?
Yes

- GO to DW14.

No

- GO to DW15.

DW14 DTCS P0053, P0054, P0055, P0059 AND P0060: CHECK FOR VPWR IN THE HARNESS

Note:If DTCs P0053, P0054, P0055, P0059, or P0060 are present, test their related circuits individually.

- Ignition OFF.

- HO2S connector disconnected.

- Ignition ON, engine OFF.

- Measure the voltage between:

image

Is the voltage greater than 10 V?
Yes

- GO to DW15.

No

- REPAIR the open circuit. CHECK the fuses.

- Clear the PCM DTCs. REPEAT the self-test.

DW15 CHECK THE HO2S HEATER FOR SHORTS IN THE HARNESS

Note:If DTCs P0053, P0054, P0055, P0059, or P0060 are present, test their related circuits individually.

- Ignition OFF.

- HO2S connector disconnected.

- PCM connector disconnected.

- Measure the resistance between:

image

- Measure the resistance between:

image

Are the resistances greater than 10K ohms?
Yes

- GO to DW16.

No

- REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

DW16 CHECK THE HO2S HEATER CIRCUIT FOR AN OPEN IN THE HARNESS

- Measure the resistance between:

image

Is the resistance less than 5 ohms?
Yes

- GO to DW17.

No

- REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

DW17 CHECK THE INTERNAL RESISTANCE OF THE HO2S HEATER

- Measure the resistance between:

image

Is the resistance between 3 - 30 ohms?
Yes

- GO to DW18.

No

- INSTALL a new HO2S.

- RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Resetting The Keep Alive Memory (KAM).

- REPEAT the self-test.

DW18 CHECK THE HO2S HEATER CIRCUIT FOR AN INTERNAL SHORT TO SIGRTN OR GND

- Measure the resistance between:

image

- Measure the resistance between:

image

Is the resistance greater than 10K ohms?
Yes

- GO to DW25.

No

- INSTALL a new HO2S.

- RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Resetting The Keep Alive Memory (KAM).

- REPEAT the self-test.

DW19 KOER DTC P1127: EXHAUST TEMPERATURE OUT OF RANGE

Note:Address all other DTCs before proceeding.

- Ignition ON, engine running.

- Engine at normal operating temperature.

- Access the PCM and monitor the HO2S Heater PID.
Is the PID state ON?
Yes

- CARRY OUT the KOER self-test.

No

- RUN the engine until the PID indicates ON.

- CARRY OUT the KOER self-test.

DW20 DTCS P0132, P0138, P0144, P0152 AND P0158: VISUALLY INSPECT THE HO2S HARNESS

Note:Disconnect the suspect HO2S harness connector. Only the suspect HO2S needs to be diagnosed.

- Ignition OFF.

- HO2S connector disconnected.

- Visually inspect the HO2S harness.
- check the connector (both halves) for contamination
- make sure the connector pins are fully seated
Is a concern present?
Yes

- REPAIR as necessary.

- Clear the PCM DTCs. REPEAT the self-test.

No

- GO to DW21.

DW21 CHECK THE HO2S SIGNAL LEVEL TOO HIGH

- HO2S connector connected.

- Ignition ON, engine running.

- Access the PCM and monitor the HO2S Signal PID.
Is the voltage less than 1.1 V?
Yes

- GO to DW22.

No

- GO to DW23.

DW22 CARRY OUT A THOROUGH WIGGLE TEST ON THE HO2S HARNESS

- Ignition OFF.

- Ignition ON, engine OFF.

- Access the PCM and monitor the HO2S Signal PID.

- Carry out a thorough wiggle test on the HO2S harness.
Does the voltage change during the wiggle test?
Yes

- REPAIR as necessary.

- Clear the PCM DTCs. REPEAT the self-test.

No

- GO to Pinpoint Test Z See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Z: Intermittent - Introduction.

DW23 CHECK THE HO2S SIGNAL FOR A SHORT TO VPWR INSIDE THE SENSOR

- Ignition OFF.

- HO2S connector disconnected.

- Ignition ON, engine running.

- Access the PCM and monitor the HO2S Signal PID.
Is the voltage less than 1.1 V?
Yes

- INSTALL a new HO2S.

- RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Resetting The Keep Alive Memory (KAM).

- REPEAT the self-test.

No

- GO to DW24.

DW24 CHECK THE HO2S CIRCUIT FOR A SHORT TO VPWR IN THE HARNESS

- Ignition OFF.

- PCM connector disconnected.

- Ignition ON, engine OFF.

- Measure the voltage between:

image

Is any voltage present?
Yes

- REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

No

- GO to DW25.

DW25 CHECK FOR CORRECT PCM OPERATION

- Disconnect all the PCM connectors.

- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.

- Carry out the PCM self-test.

- Verify the concern is still present.
Is the concern still present?
Yes

- INSTALL a new PCM. REFER to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Flash Electrically Erasable Programmable Read Only Memory (EEPROM).

No

- The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

___________________________

I realize this is extensive, but is the only way to determine what is causing the issue. Since it only happens after driving for rhirty minutes, I feel it deals with an electrical component. Heat causes metals to expand. Often times, the expansion cause a loss of connection. The hard part is locating it.

Regardless, and I am sorry to give you such a long list of tests, let me know what you find or if you run into problems or have questions.

Take care,
Joe
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Sunday, November 4th, 2018 AT 6:43 PM

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