P1151 code 1998 Mustang GT - Ford Mustang Forum
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post #1 of 12 (permalink) Old 06-11-2010 Thread Starter
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P1151 code 1998 Mustang GT

I recently bought a 98 Mustang GT 4.6 so far been a ok car. It had 17 codes when first ran, but I knew nothing of them, or how reliable they were so I had it reset then drove it for a while. Got a few new codes and cleared them by changing spark plugs, fuel pump, fuel filter, MAF sensor. Now I'm down to one, still getting a P1151 Lack of 02 switches-bank 2 sensor 1, ECM could not adjust fuel trim because of a lean or rich condition. Thats what the paper says when I had Auto Zone run the codes on it. It also has a very light tapping on passenger side of engine. I'm guessing that a new 02 sensor will fix this problem. Is this your opinion as well and if so which one is it actually? there are 4 sensors on the exhaust.
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post #2 of 12 (permalink) Old 06-12-2010
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Yeah, that's a definate O2 sensor code.

Bank 2 is the driver's side on a Mustang, just in case you didn't know. Most people assume the driver's side is bank 1, which is incorrect.

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post #3 of 12 (permalink) Old 06-12-2010
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bullitt said it. its an o2 sensor. i had that code for a long tmie before i listened to people and changed it and boom! all problems went away and picked up a cool 1 mpg
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post #4 of 12 (permalink) Old 06-14-2010 Thread Starter
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UPDATE, I changed the 2 front O2 sensors with new ones, code went away for about 20 miles then came back. It does have a miss at idle but clears up when you give just 2% of throttle. I have checked oms on all injectors and came back in spec but, when running I unplugged the 3 back injectors on the drivers side and it didn't make a difference at all till I finally unplugged the front one. So now I'm going to pull the injectors and watch them to see if they are clogged or just not spraying right. I also have done the propane test on the intake and around the throttle body and rpm never changed. Think I'm on the right track finally, the previous owner said it had problems but didn't have the money to fix them all. So now I get to find them all, but long as there is a good reward at the end it's all good.

1998 Mustang GT 4.6L SOHC , so far it's all stock, just working the bugs out right now.
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post #5 of 12 (permalink) Old 06-14-2010 Thread Starter
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::SOLVED:: I got the notion to pull the injectors and turn the engine over to check spray, the back 3 were barely misting. So I pulled them out and the inlet screen on the injectors were full of rust and debris. I carefully cleaned them out with a pin and sprayed them with sensor cleaner and put them back in. All the ponies are runnin hard on this Mustang now. Works great. Thanks to all for your help and hopefully this can help out someone else.

1998 Mustang GT 4.6L SOHC , so far it's all stock, just working the bugs out right now.
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post #6 of 12 (permalink) Old 06-14-2010
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check your spark plugs
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post #7 of 12 (permalink) Old 06-14-2010
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Originally Posted by big willy04 View Post
check your spark plugs

lets try and not post drunk......
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post #8 of 12 (permalink) Old 09-13-2011
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P1151 O2 Sensor

Hi I recived a check engine light on my dash and checked the code. It read as P151 Lack of H02S21
Switches - Sensor Indicates Lean. Does anyone know if this is the O2 Sensor and If so which sensor does the code indicate that it is? I would appreciate any information.
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post #9 of 12 (permalink) Old 09-13-2011
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P0151-HO2S Sensor Circuit Out of Range Low Voltage

Is the DTC code P1151 or P0151? The P0151/P1151 code is from the O2 front left side (driver's).

If P1151, this is likely a vacuum or exhaust leak. Rarely is this a bad O2 sensor.

The P0151 code could be a bad O2 sensor. However, it morely is caused by a wiring fault between the O2 sensor and the PCM. Any recent work?

If you are not able to find any connector or wiring problems, start by replacing the O2 sensor.

P0151 - HO2S Sensor Circuit Out of Range Low Voltage (HO2S-21)

Contaminated HO2S (water, fuel, etc)
Crossed HO2S signal/signal return wiring

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I just got the P1151 code on the way home today from work. I just put back my stock h-pipe and I have no exhaust leaks at all. Nice n quiet, double checked twice. Question? Do I need to disconnect the battery and let the PCM re-learn itself now that all the cats are back in the car? It's always ran perfect with no codes ever unless I had my prochamber mid pipe on the car...they you get the std. codes for that.

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Hello Im posting because I just got this p1151 code myself and Im trying to figure out how fix it. I'm afraid that it might be an o2 sensor that got damaged. Recently I went to a movie theater and had two people with me and my car is kind of low and the lowest thing on the undercarriage of my car is the exhaust. Anyways I went over a huge speedbump and the car scraped really hard and I actually had my passengers get out of the car so I could go over the bump and then a day later the check engine light came on. I hope that the scraping didnt damage a sensor. But I was wondering if any of you think this could be the cause or that maybe it's something else.... Thanks
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Typically I don't think you have to worry about damaging O2 sensors when you bottom out considering the wires and connectors should be handing well above your exhaust especially if we are referring to the front two and you have factory exhaust manifolds. Do you hear any new exhaust leaks since you bottomed out? It's probably worth a look and crawl under your car to look around the area were you scraped but I doubt you damaged an O2 sensor. Check for any exhaust or vacuum leaks first before you assume a damaged sensor.

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