P0171 & P0174 close b/n cigar
#1
08-12-2005, 01:49 PM
P0171 & P0174 close b/n cigar
Well I am lost??? This is the third time these problem codes have come up on my Expedition. The engine is a 5.4L all stock, 155k miles. No problems except a periodic P0171 & P0174 along wiht the occasional coil pack problem.
Anyway, I have been reading alot of posts that are similar yet also different. Like I said, this is the third time for these codes in about 4 years.
The OBD computer says P0171 solenoid bank 1, and P0174 control solenoid bank 2. The vehicle drives fine until you come to a stop where is will lope and sometimes stall. I also notice decreased power during excelleration. Both accur occasionally, not all the time. When I run it in the drive idleing, you can here an incredible hissing sound coming from the intake manifold/ throttle body area. The idle in higher than normal in this condition. Checked a few hoses seemed fine, noticed some dirk residue under the throttle body towards the front between the union with the intake manifold.
What could it be? Read a chat about cleaning the throttle body and IAC. Might give this a try first.
Any ideas would be appreciated?
Anyway, I have been reading alot of posts that are similar yet also different. Like I said, this is the third time for these codes in about 4 years.
The OBD computer says P0171 solenoid bank 1, and P0174 control solenoid bank 2. The vehicle drives fine until you come to a stop where is will lope and sometimes stall. I also notice decreased power during excelleration. Both accur occasionally, not all the time. When I run it in the drive idleing, you can here an incredible hissing sound coming from the intake manifold/ throttle body area. The idle in higher than normal in this condition. Checked a few hoses seemed fine, noticed some dirk residue under the throttle body towards the front between the union with the intake manifold.
What could it be? Read a chat about cleaning the throttle body and IAC. Might give this a try first.
Any ideas would be appreciated?
#2
08-13-2005, 12:06 AM
Welcome to the forum 
I would start by cleaning the MAF. There is some good infor in the READ FIRST FAQ thread in the 97-03 forum. I would also check the PCV hose elbows. Especially the one that is connected to the rear of the intake manifold. They are known to crack and cause a vacuum leak.
Your codes show that it is running lean on both banks.
I would start by cleaning the MAF. There is some good infor in the READ FIRST FAQ thread in the 97-03 forum. I would also check the PCV hose elbows. Especially the one that is connected to the rear of the intake manifold. They are known to crack and cause a vacuum leak.
Your codes show that it is running lean on both banks.
#5
08-13-2005, 09:37 PM
#6
08-24-2005, 04:37 AM
P0171 and P0174 Codes
Originally Posted by laddti
Well I am lost??? This is the third time these problem codes have come up on my Expedition. The engine is a 5.4L all stock, 155k miles. No problems except a periodic P0171 & P0174 along wiht the occasional coil pack problem.
Anyway, I have been reading alot of posts that are similar yet also different. Like I said, this is the third time for these codes in about 4 years.
The OBD computer says P0171 solenoid bank 1, and P0174 control solenoid bank 2. The vehicle drives fine until you come to a stop where is will lope and sometimes stall. I also notice decreased power during excelleration. Both accur occasionally, not all the time. When I run it in the drive idleing, you can here an incredible hissing sound coming from the intake manifold/ throttle body area. The idle in higher than normal in this condition. Checked a few hoses seemed fine, noticed some dirk residue under the throttle body towards the front between the union with the intake manifold.
What could it be? Read a chat about cleaning the throttle body and IAC. Might give this a try first.
Any ideas would be appreciated?
Anyway, I have been reading alot of posts that are similar yet also different. Like I said, this is the third time for these codes in about 4 years.
The OBD computer says P0171 solenoid bank 1, and P0174 control solenoid bank 2. The vehicle drives fine until you come to a stop where is will lope and sometimes stall. I also notice decreased power during excelleration. Both accur occasionally, not all the time. When I run it in the drive idleing, you can here an incredible hissing sound coming from the intake manifold/ throttle body area. The idle in higher than normal in this condition. Checked a few hoses seemed fine, noticed some dirk residue under the throttle body towards the front between the union with the intake manifold.
What could it be? Read a chat about cleaning the throttle body and IAC. Might give this a try first.
Any ideas would be appreciated?
Reggie Grayson