Lean running single cylinder 2011 Durango

Andrew Educator Indiana Posted   Latest   Edited  
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Driveability
2011 Dodge Durango Crew 3.6L (G ERB) 5-spd (545RFE) — 1D4RE4GG4BC630921
P0300 — Random/Multiple Cylinder Misfire Detected
P0301 — Cylinder 1 Misfire Detected
P0303 — Cylinder 3 Misfire Detected
P0305 — Cylinder 5 Misfire Detected
Lean Misfire

I have been given a shot at this Durango and am trying to understand a few things about the system. This is going to be a long post, I asked the boss to give me a shot at it.

Vehicle came in to the shop a few months ago with misfire codes p0300, p0301, p0303, p0305. looking at freeze frame data it is noticed that when the codes fuel trims on bank 1 are -17.5% total correction bank 2 is +12% total correction. This problem is not always consistent. However, when it does happen you can watch injector PW on bank 1 and it will start pulling fuel away from a single cylinder. Usually it is #3 but can be 1,3,or 5. If the other injectors are running at around …us PW the affected cylinder will be at 1300 or less. usually the actual misfire comes in around 1100us. If you add propane to enrichen the cylinder, it goes away.

Very early in 2019 I believe aftermarket cats were put on this vehicle for a p0420/30 code if I remember being told correctly. They were changed again do to this problem showed up shortly after this repair. The local dealership also replaced the bank 1 cylinder head for this condition. Injectors, cam sensors, coils, plugs, all have been swapped from one bank to the next. a standalone control wire for #3 injector was also ran to rule out wiring issues. The PCM has been replaced as well. oxygen sensors have also been replaced with OE.

The technician that looked at this is one of the best driveability I have seen locally.I don't question his abilities or his testing methods. In cylinder readings were done, we have scoped, inspected, checked, everything under the sun to no avail. At this point I was asked for a fresh set of eyes.

I see everything he does. I agree that it seems to be a logic issues. But my question remains is; how can a O2 operating vehicle make the determination to pull fuel from a single cylinder? and to the point that a lean misfire is present. There is no rhyme or reason, some days it runs great. I can not find any information on this so I am trying to find out how this can be.

I am making the assumption at this point it has to be off of the cam and crank readings... BUT how does a oxygen sensor vehicle know to pull from a single cylinder to make the fuel correction? Is there something so simple here I am over looking? Thanks for any and all help.

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Bryan Diagnostician
New York
Bryan
 

I would go back to basics….to a point. First what does mode 6 tell us about the misfires? Are they happening at a relatively even rate on those cyls? Or is it a few thousand on one cyl and 50 0r 60 on the others? If its even on those cyls next thing i would want to see is what rpm does it happen at? Also what causes bank to bank trim issues? Timing, exhaust restriction, and imrc operation. We…

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Andrew Diagnostician
Indiana
Andrew
 

a few hundred on one and a few on the others. 99% of the time its not even enough to flag a pending code. I have personally scoped cam and crank timing on Thursday and saw nothing. I will post some screen shots next week when I get back to the shop. I personally have not done an in cylinder but it has been performed by the other tech. And the issue remains…. it is not consistent. Good chance I…

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Nathaniel Diagnostician
Ontario
Nathaniel
 

So the question is: how many oxygen sensors got plugged in to the wrong connector when those cats were swapped?

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Andrew Diagnostician
Indiana
Andrew
 

None… not possible on this model

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Nathaniel Diagnostician
Ontario
Nathaniel
   

How exactly is it not possible? The bank 1 oxygen sensors are the same part number upstream and downstream, and the harness connectors are right beside each other. Of course it's possible. Your response tells me you haven't checked, and that you're responding without considering the voluntary help someone is offering. Considering the thousands of dollars sunk into not fixing this vehicle, maybe…

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Andrew Diagnostician
Indiana
Andrew
 

the placement of the harnesses makes it not possible not enough length. perhaps because of this we have a placement issue of the o2 on the aftermarket cat…. I have looked. and we would have many more issues. Reading the information given would be a dead give away. While i appreciate the response being condescending gets us no where. thanks for the reply.

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Justin Technician
California
Justin
 

When you first typed in problems after cat install the o2 placement on aftermarket cat has been discussed and proven to have the ability to skew the correction ability from computer . Maybe just maybe something funny with the way it was built ??

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Andrew Diagnostician
Indiana
Andrew
 

it is very possible. I wish I had the original to compare, however this was done before I was employed. I am hoping a similar vehicle comes in so I an compare and make some measurements.

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Kent Mechanic
South Dakota
Kent
 

One thing to remember is if a cylinder is misfiring, the computer will shut that injector off to save the catalytic converter. That could be the reason for fuel being pulled away from only one particular cylinder.

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Andrew Diagnostician
Indiana
Andrew
 

Absolutely, but the misfire is not present even in mode 6 until the fuel is being pulled away

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Bryan Diagnostician
New York
Bryan
 

Have you been able to scope cam/crank during misfire? If the crank signal is walking back and forth you could be dealing with a broken flexplate. I've had a few shifting crank tone wheels in my career, very hard to prove out. None of that explains the excessive air flow on the opposite bank though

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Andrew Diagnostician
Indiana
Andrew
 

I did on Thursday before we left, and I did not see anything out of the ordinary…. but I will make captures and post for you. I was doing it close to the end of the day trying to get some baselines for myself to see.

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Jamey Owner/Technician
California
Jamey
 

You have inverse fuel trims. Follow that and do what Albin suggested.

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Albin Diagnostician
Washington
Albin
 

Please put up some scan tool data for the fuel trims. I would really like to see a FRTD capture of the trims. With this information, a lot of guessing could be alleviated

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Andrew Diagnostician
Indiana
Andrew
   

tell me everything you would like to see and next week I will get you anything you would like to analyze. This only occurs at idle to my knowledge…. I should have said that earlier

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Albin Diagnostician
Washington
Albin
 

Start here, then ask questions. diag​.​net/msg/m61bqk58h6…

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Charles Technician
California
Charles
 

You are correct in that it is logic based. One thing that PCM does on that particular engine that is not disclosed in a lot of diagnostic data is that the spark plug burn time on each cylinder is monitored through the coil signal wire, just like if it was hooked to a DSO, to monitor the secondary firing line. If you are using the factory witech2 scan tool you can watch and compare between…

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Andrew Diagnostician
Indiana
Andrew
 

This is very informative. I long suspected that ignition monitored this. I remember seeing burn time on some of the older Dodge products. I have not seen it on the newer. (with a AM scanner anyways) I do have the WI-Tech at work and will look next week. I actually stumbled across your response to a similar issue on another platform. And that helped bring it all home. This is a idle issue. I…

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Charles Technician
California
Charles
 

I would check the repair history when they did the cylinder head and see if they replaced the lifters when they had the head off. Most Dealers do not replace them anymore as they were chastised and charged back by Chrysler for “over repairing” the vehicle. If just one lifter, usually an exhaust, is stuck in an partially extended position, it will not make noise, and it effects the intake…

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Ray Diagnostician
Ontario
Ray
   

To find valve train issues, use pressure transducers in the exhaust and in the intake while cranking. This is a good capture from a 2014 Caravan 3.6, The blue channel is a pressure transducer in the tailpipe to compare each cylinder's exhaust stroke pulses. The green channel is a pressure transducer in the intake to compare each cylinders intake stroke pulses. The yellow channel is the…

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Andrew Diagnostician
Indiana
Andrew
 

Thank you! I will be doing some more testing as time allows. We have this vehicle to see it through until repair.

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Stephen Technician
Tennessee
Stephen
 

That has got to be the TEXT BOOK version of an RC with exhaust and intake waveform. Do you think that the smaller hump in the exhaust is from the overlap of the intake valve?

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Craig Technical Support Specialist
Illinois
Craig
 

Stephen, I believe what we are seeing is the exhaust valve closing point during the overlap event, if I am incorrect someone please step in. I understand that there will be variations due to design intake or exhaust but I believe that the overlap points should be closely examined, in Ray's first example everything is gorgeous and repeating. The exhaust pattern in the second example though shows…

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Ray Diagnostician
Ontario
Ray
 

The pattern shows one bank with higher exhaust pressure pulses because of the exhaust system. The problem with the vehicle was an intermittent misfire on acceleration with no codes. The second capture shows the misfiring spark plug during a brake torque.

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Stephen Technician
Tennessee
Stephen
 

Craig, Good evening, On Ray’s first photo, I noticed that the small hump on the exhaust seemed to copy the intake waveform, displayed below it. I wondered if the point of ascending of the small hump was the intake opening( that point coincides with the ignition pulse which would be a little before TDC), and the point of the small hump descending is the closing of the exhaust valve? The apex of…

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Stephen Technician
Tennessee
Stephen
 

Ray, This has got to be the text book version of an RC with intake and exhaust capture. Do you think that the small hump on the exhaust waveform is from the intake overlap?

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Ray Diagnostician
Ontario
Ray
 

On some vehicles, the exhaust waveforms are affected by the exhaust systems. This is a good cranking capture from a 2010 Buick 3.6 and the front bank's exhaust manifold is farther away to the end of the tailpipe than the rear bank's exhaust manifold. The green CH C is the pressure transducer in the tailpipe. The black CH D is the starter amps.

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Greg Technician
Washington
Greg
 

Fuel sample.

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Andrew Diagnostician
Indiana
Andrew Update
 

I want to post the update and fix on this vehicle finally. Wanted to make sure we were clear before I did. I want to apologize for not having scope/scan data to back this up. During the fixing of this vehicle the hard drive on the shop scope computer died. Shame on me but I should have backed it all up. If when the computer comes back it still has any of the saved files left I will update. My…

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