5.7 upstream Oxygen Sensor P0132

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toyv84x4

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so I've had it a week
today got P0132 code on scanner (1/1 - driver side upstream before cat)
cleared the code but came back again
so either bad O2 sensor 56028994AA (5.7 SLT 4x4)
or could it be worse?

I heard the PCM could be a problem? You buy a used truck and fine for a week then suddenly O2 sensor codes? Could the PCM have been reset and therefore it took a week to show up? Might that mean a bad PCM?

I will try the O2 when I get the part (shipped to UK or pay 5 times as much for one here in the UK) - wiring looked ok in the dark - may try a live scan and some carb cleaner in a vacuum hose.
 

xb1230

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So here is what I would do:

Clear the code, clean the TB (be careful as the 5.7 TB has lots of electronic embedded, you can find lots of instructional videos and post here on the forum on that topic), and I would also check the plugs. If they are not copper core then they may be part of the problem.

Of course check that the wiring from the PCM to the sensor is not cracked, or broken.

To assess if the issue really is the O2 sensor, try swapping them from one side to the other (I do believe they are the same on both sides, maybe someone will chime in to correct me here). If the code persists and follows the moved sensor then you have your diagnostics.

If you have an OBDII bluetooth adapter and an Android device you can try the Torque app which can give you live data reading capabilities and you could display the sensors's reading and compare to one another. It would also allow you to see if there were any other codes in the ECU that could lead you to another issue hidden under the O2 sensor code.

Hope this helps
 

RonJon '06

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^ The nice thing about swapping the front o2 sensors is that it doesn't cost anything other than 15 min under the hood and the only risk would be damaging the sensors or wiring. If you replace the o2 sensor I would go with NGK, not Bosch. If its not the o2 sensor then I would check for an intake manifold leak, exhaust leak or a leaky fuel injector.
 
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toyv84x4

toyv84x4

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Great tip to swap O2 sensors.
It started hopping which may be misfire so I have ordered a new set of plugs for starters. May be the mixture due to the O2 but I don't know the age of the plugs.
Will update in a few days. Thanks
 

freddyx844

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Exhaust gases are hotter on lpg. Do you have the same issue when running on petrol? The local import dealers might have stock.



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toyv84x4

toyv84x4

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Chrysler use the same oxygen sensor 56028994AA on some of their 5.7 engines like the Jeep Grand Cherokee and 300C so they can get locally in a couple of days. Will do the plugs and have a good clean and wire check, clear codes and then if I get the error I will switch sensors to see if it swaps sides. I can't tell if either LPG or gasoline is causing the code as been using both but I don't like the misfire at idle but it comes and goes.
 
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toyv84x4

toyv84x4

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Update: Changed the 4 plugs on the first two driver side cylinders. It's too cold and dark to continue and I only wanted an initial inspection. Results were one fair worn plug, one nearly fully closed gap fair worn plug, two normal worn plugs. No anti seize was on there. I can only guess that the plug was dropped in by the original fitter and the gap closed. Either that or running LPG or 95 octane UK gasoline causes detonation. You can see the plug gap was like that a long time as it's worn in the sloped position it was set/dropped to. The worst of the plugs were both the ones under the coil packs so I guess this is normal? On running, hesitation / hop has gone and appears smoother (although this may be because the computer has reset and codes cleared. Once I get all plugs done I will see if the P0132 comes back and then get on to the oxygen sensor. At least I can see the deal with changing plugs.
 
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toyv84x4

toyv84x4

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Yes I used anti seize and silicone on the boot. Pre-loved trucks. The loving starts here
 
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toyv84x4

toyv84x4

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So I have done all the plugs (easy ones) except the back two drivers side under the brake booster. The rain, the cold, the LPG kit stuck in the way over all the plugs etc only gives me an hour here and there. I expect the last two cylinders to be the worst plug wear / gap close (pre-lover plug dropping efforts) , so can't wait to get onto them.

Also I have noticed a few of the rear manifold bolt-heads are snapped off. I see that's common so I now know where the extra tapping noises come from but little gas leakage if at all so I can live with that. They look like they rotted from heat and stress on the exhaust system / tailpipe catching the ground.

I can now hear an electrical sound / whine from either the fan / alternator or pulleys. I suspect the tension idler pulleys as all the pulley faces were strangely rusty on this truck so could be the bearings are shot. All in all this pre-loved truck is coming together and repairs making sense according to the condition. I will add new idlers, a belt and sort the O2 sensor and see if everything is then resolved. In a way I prefer to know my trucks inside out so don't mind what I've found so far. The Hemi is still making me smile.
 
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toyv84x4

toyv84x4

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So the "difficult" plugs under the brake booster turned out to be easy. My problem was the LPG hoses and rail that was bolted over the top of the coil packs. Once out the way this side was a piece of cake (maybe because I'm right handed) but short extension, plug socket and ratchet was the only combination required. Lucky most of you guys in the US don't need to run on LPG Butane.

Results: All plugs showed none to normal / slight wear. The second cylinder in from the front on the drivers side had a closed gap and the third cylinder had a very wide gap. I still wonder what caused the closed gap - human or engine running - see pictures.

The spark plugs did not resolve the O2 sensor code which came back. I was about to swap the O2's from side to side but looking at the amount of rust to the outside of it I decided just to get another. Stupid maybe, as now the new one may mask any other issues that caused the O2 to flag the code. The old sensor came out with a wrench without a struggle. The electrical connector was tricky as the plastic becomes brittle - just make sure you press hard on the tab then pull and the tab will stay pressed in as the plug starts to slide off.

Hopefully it was just a failed O2 sensor and things will be good for some time and there are no underlying issues. I know the snapped off bolt heads on the manifolds may cause some bad readings due to leaks. I hope I don't need to tweak them; those bolts into the head look like a disaster waiting to happen.

Codes are currently clear after a couple of cycles and engine is smooth as silk with no symptoms experienced before. I guess one or two more trips will give the all clear...or not as that's when they came back before. Without testing the old O2 at least it looks bad which suggests it was contaminated.
 

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toyv84x4

toyv84x4

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End Result.
New O2 sensor appears to have solved the issues.
Nice to know it has correct gapped new plugs, runs smooth, no codes, more power, more mpg.
 

Redtruck-VA

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The exhaust manifold bolts can be reached relatively easy with the inner fender wells removed. Use OEM gaskets as they are better than anything else available. The spark plug gap usually grows at .001 per 2000 miles. I use NGK 4306 without issue. They are one range colder than stock. Good luck..
 
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xb1230

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I was told the Exhaust manifold gaskets were made by FelPro and they were much cheaper to get with the same quality as the OE Dodge ones.

But I have seen the OE ones and they are thicker than many of the aftermarket I have seen, but have not seen the FelPro to compare to the OE so can't say from first hand experience.

Glad you were able to sort thnigs out and have it run smooth with new Plugs and O2 sensors.

Keep up the good work.
 

Redtruck-VA

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Can't honestly say I've put the Felpro side by side with the OEM gaskets. The gaskets that come with the headers are inferior.
 
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