2001 Lincoln LS V8 Catalytic Converter question

AmsterDutch said:
The reason your running Rich and its showing the DTC PO172 code ...
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Misfires can and do trigger lean codes. Why lean? Because O2 sensors read left over oxygen, not fuel. Misfire = no combustion = lots of left over oxygen = looks like lean mixture to the PCM.

P0172 is a rich mixture code. It won't be triggered by misfires.

I wonder if you have a leaky injector that isn't closing all the way all the time? It would fit the symptoms and your readings above.
 
joegr said:
Misfires can and do trigger lean codes. Why lean? Because O2 sensors read left over oxygen, not fuel. Misfire = no combustion = lots of left over oxygen = looks like lean mixture to the PCM.

P0172 is a rich mixture code. It won't be triggered by misfires.

I wonder if you have a leaky injector that isn't closing all the way all the time? It would fit the symptoms and your readings above.
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Would I see any gas on the top of the injectors (shinny spots I mean) If so I don't see any I tried my best to shine my camera flash down there and did not see anything that looked shinny.
 
DaleGrib said:
Would I see any gas on the top of the injectors (shinny spots I mean) If so I don't see any I tried my best to shine my camera flash down there and did not see anything that looked shinny.
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I wouldn't expect that you would. I think that the leak would be out the nozzle where the gasoline normally comes out. You might be able to find it with a mechanic's stethoscope. I think that the bad one might sound different than the rest.
 
joegr said:
I wouldn't expect that you would. I think that the leak would be out the nozzle where the gasoline normally comes out. You might be able to find it with a mechanic's stethoscope. I think that the bad one might sound different than the rest.
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I have a whole set of oem injectors if any are bad I will just replace them all to be safe.
 
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“Ignition misfires, like mechanical misfires, cause puffs of oxygen to keep hitting the Oxygen Sensors. Since the sensors will think the mixture is running lean, the PCM will add fuel to the mixture. “
Thus causing your car to run rich....
 
AmsterDutch said:
“Ignition misfires, like mechanical misfires, cause puffs of oxygen to keep hitting the Oxygen Sensors. Since the sensors will think the mixture is running lean, the PCM will add fuel to the mixture. “
Thus causing your car to run rich....
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Since the sensors think the mixture is running lean, they would give a lean code, not a rich code. How much experimentation have you done on this to reach the opposite conclusion?
 
joegr said:
Since the sensors think the mixture is running lean, they would give a lean code, not a rich code. How much experimentation have you done on this to reach the opposite conclusion?
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"When the computer receives a rich signal (high voltage) from the O2 sensor, it leans the fuel mixture to reduce the sensor’s reading. When the O2 sensor reading goes lean (low voltage), the computer reverses again making the fuel mixture go rich. This constant flip-flopping back and forth of the fuel mixture occurs with different speeds depending on the fuel system."
So what am I not understanding because if I'm hearing this article correctly when my LS is producing a P0172 Rich code its because there's too much air going through the O2 sensor which tells the PCM to add more fuel ...when the Computer adds more fuel I'm then going to be running Rich? Hence when the sensor reads too much fuel compared to Air ratio then the PCM will produce the P0172 Code.. I guess I'm willing to learn if I'm wrong and if I'm comprehending this wrong please explain to me how and why my LS is Producing the P0172 Rich code? I guess I might not be comprehending this science and I've been looking at it backwards
 
Too much air produces a lean code. A lean code is because the PCM enriched the fuel mixture till it reached the limit, while still reading too much air. (At this point, if the too much air was due to misfires, the mixture will indeed be rich, but the PCM will still think that it is lean.) It does not ping pong between lean and rich. Too much air will not produce a rich code.

A rich code indicates some other problem, not misfires. (Misfires may be caused by whatever is causing the rich condition.)
 
joegr said:
Too much air produces a lean code. A lean code is because the PCM enriched the fuel mixture till it reached the limit, while still reading too much air. (At this point, if the too much air was due to misfires, the mixture will indeed be rich, but the PCM will still think that it is lean.) It does not ping pong between lean and rich. Too much air will not produce a rich code.

A rich code indicates some other problem, not misfires. (Misfires may be caused by whatever is causing the rich condition.)
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That makes sense ...you just gave me some hope I’ll hopefully figure this out Tomorrow when the Blue Driver Scanner arrives
 
Well went to a shop this morning the only read my car with a reader and said you have a bad cat. Thankfully they did not charge me! I am tired of these mechanics that think the only way to find a problem in a car is to read the codes..... So with that being said I am going to take my car to my dad's house and we are gonna attempt to change out the fuel injectors ourselves. I am also gonna take out the EGR and clean it up really good and see if that helps. What is the best thing to use to clean it?
 
Yep, reading the codes is just one of the steps in diagnosing a problem.
Throttle body cleaner should work. These don't seem to carbon up too much.
 
DaleGrib said:
Well went to a shop this morning the only read my car with a reader and said you have a bad cat. Thankfully they did not charge me! I am tired of these mechanics that think the only way to find a problem in a car is to read the codes..... So with that being said I am going to take my car to my dad's house and we are gonna attempt to change out the fuel injectors ourselves. I am also gonna take out the EGR and clean it up really good and see if that helps. What is the best thing to use to clean it?
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Good to hear you found the culprit ...these catalystic converters are very problematic on the Lincolb LS due to the Finiky COP's and plugs
 
DaleGrib said:
Well went to a shop this morning the only read my car with a reader and said you have a bad cat. Thankfully they did not charge me! I am tired of these mechanics that think the only way to find a problem in a car is to read the codes..... So with that being said I am going to take my car to my dad's house and we are gonna attempt to change out the fuel injectors ourselves. I am also gonna take out the EGR and clean it up really good and see if that helps. What is the best thing to use to clean it?
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I'm actually hoping my problems are that easy lol
 
DaleGrib said:
The thing is though bro they didn't help me out a bit lol I have been to have my cat's checked like 3 times now and they say they are good.
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I’m not understanding this I guess...you said you went to a shop this morning and they said your Cat was bad but yet you said they said it’s good? Are you trying to say you’re getting different information from multiple shops? How do they know your Catalyistic system is good or how do they know it’s bad ...I would start asking for read outs and fuel pressure diagrams and have them explain why they’re coming to these conclusions? Did they do a smoke test today? Did they do a compression test on your injectors?
 
AmsterDutch said:
I’m not understanding this I guess...you said you went to a shop this morning and they said your Cat was bad but yet you said they said it’s good? Are you trying to say you’re getting different information from multiple shops? How do they know your Catalyistic system is good or how do they know it’s bad ...I would start asking for read outs and fuel pressure diagrams and have them explain why they’re coming to these conclusions? Did they do a smoke test today? Did they do a compression test on your injectors?
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Bro they didn't do anything but read a code they did not try to check anything out and then I went to the cat shop and they said they highly doubt the cat is bad. I have had them check it out several times now that is what I meant. Also I am pretty sure I overheard them saying the fuel injectors were harder to do than they had thought. I really got the vibe they didn't want to do the work. But now from another thread today I think I might have found atleast part of my problem due to the gap being wrong on all 8 plugs. They are gapped to .44 which @joegr kindly pointed out was wrong. I got bad info from advance auto but I got a set of new plugs that are gapped at .40 that should be within the proper range that the LS likes. The Ford place parts dept, Advance auto and autozone all said the gap should be .44 but when I called back and talked to a service advisor at the ford place they said the range would be ok from anywhere from .39 to .43 and they admitted their parts dept had the wrong info.
 
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DaleGrib said:
Bro they didn't do anything but read a code they did not try to check anything out and then I went to the cat shop and they said they highly doubt the cat is bad.
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Ha Ha Ha Too funny...not trying to be sarcastic and rude at Allen bro but DAMN! ...remind me to never take my LS to a Shop where you’re from because they’re either total simpiltons or the laziest Machanics on earth....look you need to change out those COP’s and plugs and then start fresh and if need Ben travel to a city that has actually mechanic with the proper tools and knowledge to work on the Jag
 
AmsterDutch said:
Ha Ha Ha Too funny...not trying to be sarcastic and rude at Allen bro but DAMN! ...remind me to never take my LS to a Shop where you’re from because they’re either total simpiltons or the laziest Machanics on earth....look you need to change out those COP’s and plugs and then start fresh and if need Ben travel to a city that has actually mechanic with the proper tools and knowledge to work on the Jag
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I understand I have the same feeling quite honestly that is why I won't go to many places. My one mechanic that knows his stuff is very busy or I would have had him do all this. He is one of the cheapest around. Did my complete coolant system change out including the radiator for $250 (for labor I mean) I did find a good Jaguar shop in town they just have a 2 week waiting period to get into their shop.
 
DaleGrib said:
I understand I have the same feeling quite honestly that is why I won't go to many places. My one mechanic that knows his stuff is very busy or I would have had him do all this. He is one of the cheapest around. Did my complete coolant system change out including the radiator for $250 (for labor I mean) I did find a good Jaguar shop in town they just have a 2 week waiting period to get into their shop.
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Well, you know what to do next change out COP’s and plugs and then make an appointment with your regular mechanic ...how has the car been running and driving as of today?
 
AmsterDutch said:
Well, you know what to do next change out COP’s and plugs and then make an appointment with your regular mechanic ...how has the car been running and driving as of today?
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The plan is to change out the plugs and coils and throw a bottle of STP fuel injector cleaner in and if that does not make my issue go away then we will change out the injectors. I have a friend that is going to help me do them if needed. I mean I have the injectors so might as well try them since it won't cost anything. Plus I am sure it would not hurt to have a good set of injectors in that are clean. If all that does not improve it then for sure it's going into that one shop or out of town to a good shop.
 
joegr said:
Misfires can and do trigger lean codes. Why lean? Because O2 sensors read left over oxygen, not fuel. Misfire = no combustion = lots of left over oxygen = looks like lean mixture to the PCM.

P0172 is a rich mixture code. It won't be triggered by misfires.

I wonder if you have a leaky injector that isn't closing all the way all the time? It would fit the symptoms and your readings above.
Click to expand...

@joegr Them plugs that are gapped at .44 would likely play a part in my long cranking, misfires and the cat code right?
 
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DaleGrib said:
The plan is to change out the plugs and coils and throw a bottle of STP fuel injector cleaner in and if that does not make my issue go away then we will change out the injectors. I have a friend that is going to help me do them if needed. I mean I have the injectors so might as well try them since it won't cost anything. Plus I am sure it would not hurt to have a good set of injectors in that are clean. If all that does not improve it then for sure it's going into that one shop or out of town to a good shop.
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Have you disconnected your MAF sensor and tried to start the car?
 
AmsterDutch said:
Have you disconnected your MAF sensor and tried to start the car?
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I have at one point I can't remember what happened though. I know I had tried a few of them types of tests and they did not help at the time.
 
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