Codes P0171 and P0174
#1
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I haven't been able to find anything in the forum, so I'm hoping someone might have an answer for me. I have a 2004 X-TYPE 3.0L with 118,000 miles on it. I've been driving this car for about 2 years now, and the CEL comes on and off randomly, along with the ABS light. I recently had it put on a scanner and it shows error code P0171 and 0174, and an open fault on the front passenger wheel. The car runs fine, no missing or rough idle. Every so often, when I first drive it after a rain, it will start a bad stuttering if I accelerate to quickly. I just have to back off the gas a bit and ease it into what I think is third gear, after which, it does fine. Also, does anyone know if I can just replace the wheel speed sensor or do I need to replace the cable also? Sorry for the length, hope someone can help. Thanks.
#2
#3
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The codes indicate you are running a lean condition on both banks.There are common vacuum leak points for the X-Type.
1. The PCV Hose running from the forward cam cover to the intake manifold.
2. The brake booster check valve and vacuum line.
3. The IMT O-rings at the end of the intake manifold.
4. The intake manifold gaskets.
The stuttering is the engine going into fail safe mode to prevent engine damage.
1. The PCV Hose running from the forward cam cover to the intake manifold.
2. The brake booster check valve and vacuum line.
3. The IMT O-rings at the end of the intake manifold.
4. The intake manifold gaskets.
The stuttering is the engine going into fail safe mode to prevent engine damage.
#4
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The codes indicate you are running a lean condition on both banks.There are common vacuum leak points for the X-Type.
1. The PCV Hose running from the forward cam cover to the intake manifold.
2. The brake booster check valve and vacuum line.
3. The IMT O-rings at the end of the intake manifold.
4. The intake manifold gaskets.
The stuttering is the engine going into fail safe mode to prevent engine damage.
1. The PCV Hose running from the forward cam cover to the intake manifold.
2. The brake booster check valve and vacuum line.
3. The IMT O-rings at the end of the intake manifold.
4. The intake manifold gaskets.
The stuttering is the engine going into fail safe mode to prevent engine damage.
#5
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James, those are not bad things to check, but, odds are, they are not going to fix things. It sounds like you replaced the PCV valve hose (about the same diameter as your thumb that runs parallel to the throttlebody). If you look at the brake booster, there is a line that comes off of that and runs to the top of the engine. Thta would be the next thing I replace. After that, I would be looking at the IMT valve o-rings.
As for your stutter after a rain, odds are, you have a seal on a coil that is leaking and is allowing water to get into the plug well. This will cause the spark to jump to the wrong area and cause a cylinder to loose power (hence your stutter). The trick will be to push the car hard enough to cause it to throw up a code so you know what cylinder is allowing water into the plug well. It will go away shortly after driving the car because the enigne gets warm enough that you evaporate the water away.
As for your stutter after a rain, odds are, you have a seal on a coil that is leaking and is allowing water to get into the plug well. This will cause the spark to jump to the wrong area and cause a cylinder to loose power (hence your stutter). The trick will be to push the car hard enough to cause it to throw up a code so you know what cylinder is allowing water into the plug well. It will go away shortly after driving the car because the enigne gets warm enough that you evaporate the water away.
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Sheff928 (11-24-2020)
#6
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Code P0171 and P0174 are almost always vacuum leaks, MAF sensor or PCV valve. PCV valves are inexpensive and easy to replace so that is the first thing I would do. Next, clean the MAF sensor but, be sure to use MAF sensor cleaner and not something like carburetor or brake cleaner or WD40 which will likely ruin the sensor. You cam also test the MAF sensor, there are instruction on YouTube on how to do it with a voltmeter. Last, check for vacuum leaks.Sometimes they are easy to find and some times they are not, shops use a smoke machine to pinpoint the leak or they can use LP spraying carefully around the engine vacuum hoses and when the car suddenly starts running better you can see where the leak is. On a different car (Expedition) I had the exact same problem, I did the first two steps myself with no luck and my mechanic did the third using LP and found a leak on the throttle body which he fixed; car running perfectly now.
#7
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Code P0171 and P0174 are almost always vacuum leaks, MAF sensor or PCV valve. PCV valves are inexpensive and easy to replace so that is the first thing I would do. Next, clean the MAF sensor but, be sure to use MAF sensor cleaner and not something like carburetor or brake cleaner or WD40 which will likely ruin the sensor. You cam also test the MAF sensor, there are instruction on YouTube on how to do it with a voltmeter. Last, check for vacuum leaks.Sometimes they are easy to find and some times they are not, shops use a smoke machine to pinpoint the leak or they can use LP spraying carefully around the engine vacuum hoses and when the car suddenly starts running better you can see where the leak is. On a different car (Expedition) I had the exact same problem, I did the first two steps myself with no luck and my mechanic did the third using LP and found a leak on the throttle body which he fixed; car running perfectly now.
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#8
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Now I'm getting these two codes, car also runs rough on start up which it never has done. I also get a "cruise control won't work" yet it works fine.
I'll clean the MAF and try Vern's suggestions:
1. The PCV Hose running from the forward cam cover to the intake manifold.
2. The brake booster check valve and vacuum line.
3. The IMT O-rings at the end of the intake manifold.
Where is the MAF sensor if I may ask?
I'll clean the MAF and try Vern's suggestions:
1. The PCV Hose running from the forward cam cover to the intake manifold.
2. The brake booster check valve and vacuum line.
3. The IMT O-rings at the end of the intake manifold.
Where is the MAF sensor if I may ask?
Last edited by Mr rx-7 tt; 12-16-2020 at 03:59 PM.
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#11
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The car was cold, sitting over night, so I started it up and began looking under the hood at problem area Dell and Chris suggested. The first area I checked was the IMT O-rings. Bingo...You could actually hear the air leaks. When you run your hand over the IMT and intake you could also hear it. With a big smile on my face happy this was going to be an easy fix I ran down to the dealer and paid my $17.65 for the two green O rings and replaced the top one. I then proceeded to replace the second and found out the upper intake manifold needs to come off to replace it. I guess I could file the plastic down but I would rather do it the right way. I then passed a kidney stone. (The smile came off my face, LOL)
The Jag has ~75,000 miles so it's due for plugs, a reseal on the valve covers as they are slightly leaking as I can smell oil at times and a belt chance and idler pulley change, all original. I also need to change the transmission oil. Dealer wants $2500-$2700 for the valve covers and plug change, Indy wants ~$1500. I'll save the money and do it myself hopefully it can wait until spring...I really like the little Jag, it excels as an interstate car and it also gets good gas mileage. These cars in my opinion are underrated. I bought mine new, ordered it and so far has given me few issues to speak. I have replaced the fuel pump, the leaking radiator (Nissen), a couple coolant hoses, the water pump, tires and brakes.
The Jag has ~75,000 miles so it's due for plugs, a reseal on the valve covers as they are slightly leaking as I can smell oil at times and a belt chance and idler pulley change, all original. I also need to change the transmission oil. Dealer wants $2500-$2700 for the valve covers and plug change, Indy wants ~$1500. I'll save the money and do it myself hopefully it can wait until spring...I really like the little Jag, it excels as an interstate car and it also gets good gas mileage. These cars in my opinion are underrated. I bought mine new, ordered it and so far has given me few issues to speak. I have replaced the fuel pump, the leaking radiator (Nissen), a couple coolant hoses, the water pump, tires and brakes.
#12
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Mr rx-7 tt (12-19-2020)
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