CEL Bank 1 and 2 lean p0171 p0174 HELP PLEASE
#1
CEL Bank 1 and 2 lean p0171 p0174 HELP PLEASE
Hello all. Long time no see.
I need to pass inspection. I have searched and searched. Found possible problems. From what I can figure my problem is some sort of vacuum leak. As that is the most likely problem for those codes both coming up together.
Here is what I have done so far.
Checked all hoses for visual cracks or leaks. Maybe not all hoses but all the ones I could find.
I don't have vacuum hubs any more but those were removed years ago this CEL came on within the last 2 months.
Replaced PCV since it could have been a problem and only cost 3 bucks.
Cleaned MAF.
Cleaned sensor in intake after MAF. (forgot what thats called)
I have also sprayed down the engine bay with brake cleaner and can't seem to find the problem. But I don't necessarily think that rules out vacuum leak.
I have also dumped in a bottle of injector cleaner but doubt the injectors are the problem since the truck runs strong without any hesitation.
Also. My heat/ac doesn't work correctly but hasn't worked correctly for about 3 years. The blend door doesn't always work right. It blows defrost and floor most of the time. If I turn on the 4 low it will blow out the vents and will stay on the vents for 30 minutes then back to the def/floor. I don't drive around in 4 low all the time. I just switch it over then back to 2wd. This problem occured first when i did a cowl snorkel. I know that problem and it has to do with the vacuum canister. I did my best to feel up into the fender and check it and all feels fine. I didn't want to remove the fender if I didn't have to since it is a pain to get back on and I am not sure I will get it back on since it is bent now.
Okay so what course of action should I go with next???
Fuel filter??
Replace intake manifold gasket??
Replace O2 sensors??
Should I pull my plugs and see if they tell me anything? I prolly should replace them anyhow but I suspect this won't get me through inspection.
Thanks in advance.
I need to pass inspection. I have searched and searched. Found possible problems. From what I can figure my problem is some sort of vacuum leak. As that is the most likely problem for those codes both coming up together.
Here is what I have done so far.
Checked all hoses for visual cracks or leaks. Maybe not all hoses but all the ones I could find.
I don't have vacuum hubs any more but those were removed years ago this CEL came on within the last 2 months.
Replaced PCV since it could have been a problem and only cost 3 bucks.
Cleaned MAF.
Cleaned sensor in intake after MAF. (forgot what thats called)
I have also sprayed down the engine bay with brake cleaner and can't seem to find the problem. But I don't necessarily think that rules out vacuum leak.
I have also dumped in a bottle of injector cleaner but doubt the injectors are the problem since the truck runs strong without any hesitation.
Also. My heat/ac doesn't work correctly but hasn't worked correctly for about 3 years. The blend door doesn't always work right. It blows defrost and floor most of the time. If I turn on the 4 low it will blow out the vents and will stay on the vents for 30 minutes then back to the def/floor. I don't drive around in 4 low all the time. I just switch it over then back to 2wd. This problem occured first when i did a cowl snorkel. I know that problem and it has to do with the vacuum canister. I did my best to feel up into the fender and check it and all feels fine. I didn't want to remove the fender if I didn't have to since it is a pain to get back on and I am not sure I will get it back on since it is bent now.
Okay so what course of action should I go with next???
Fuel filter??
Replace intake manifold gasket??
Replace O2 sensors??
Should I pull my plugs and see if they tell me anything? I prolly should replace them anyhow but I suspect this won't get me through inspection.
Thanks in advance.
#2
its super easy to find the vacuum leak, just leave your truck idling find the hissing sound an see the collapsed hose which is more than likely going to be the 90 degree bend at the front of your intake manifold, i dont have a picture of it anywmore but go take a second look with the engine running, you should see/hear it
#4
#6
I checked over the vac lines at the throttle body...I guess I will check them again.
I am also going to replace the fuel filter and see if that fixes it. If that is a no go then I am going with intake gaskets.
Anyone have the part number for the intake gaskets so I don't get the wrong ones from Advance.
I am also going to replace the fuel filter and see if that fixes it. If that is a no go then I am going with intake gaskets.
Anyone have the part number for the intake gaskets so I don't get the wrong ones from Advance.
#7
#10
Interesting. The explorer started acting up before the codes came. On cold mornings it would run rough when accelerating until it warmed up, couldn't figure out why. Apparently the rubber intake manifold gaskets leaked just a little when cold. As they warmed up they became more pliable and sealed up, ran fine. When the CEL finally came on it made sense.
#12
I will not spend over $100 when there are several other things that seem more likely that I can fix that don't total $50.
It is a bit foolish to replace O2 sensors first. It doesn't make the most sense since it is unlikely that both O2 sensors would fail at the exact same time. When I first checked the code it was Bank 1 and Bank 2. It's not like one code came up then the other. I checked the code within 2 days of it popping up.
I am not rulling it out all together...just as the last option once I have exhausted all other possibilities.
#13
My mom's explorer is throwing one of those codes too. Her's is lean on bank one. I just cleared the code and no more CEL. I know its not the way you want to do it though.
I looked all over her explorer and couldnt find any bad hoses. I believe it might be the o2 sensor on her 4.0L. Lets hope thats not the case on yours.
I looked all over her explorer and couldnt find any bad hoses. I believe it might be the o2 sensor on her 4.0L. Lets hope thats not the case on yours.
#14
My mom's explorer is throwing one of those codes too. Her's is lean on bank one. I just cleared the code and no more CEL. I know its not the way you want to do it though.
I looked all over her explorer and couldnt find any bad hoses. I believe it might be the o2 sensor on her 4.0L. Lets hope thats not the case on yours.
I looked all over her explorer and couldnt find any bad hoses. I believe it might be the o2 sensor on her 4.0L. Lets hope thats not the case on yours.
Being that you have only 1 bank lean it makes complete sense that you have 1 bad O2 sensor.
#16
#17
I had the same two codes two weeks ago. Turned out I had a seal on bottom of my oil cap causing an un-metered air leak behind the MAF which thru the codes. Picked up a new cap and its been fine after clearing codes.
Anytime you get a lean bank 1&2 it has to be a vac leak or a inlet leak somewhere after the MAF.
Anytime you get a lean bank 1&2 it has to be a vac leak or a inlet leak somewhere after the MAF.
#20
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