Help! Misfiring, Stumbling, Rough Idle, And Loss Of Power

Amber Midkiff

Member
Sep 6, 2015
23
1
13
24
West Virginia
Merry Christmas my fellow gearheads! I have some major mustang problems and I'm hoping someone can help me, you all always have good advice and I've always had good luck with this forum. So here's the issue. I have a 2001 Mustang GT 4.6 SOHC with 130,000 miles on it. Within the past 4 months I have replaced the following:
- Fuel Pump.
- Fuel Filter.
- Fuel Pressure Sensor.
- IAC Valve.
- Throttle Position Sensor.
- EGR Valve.
- MAF Sensor.
- PCV Valve.

My engine has been ticking for the past 30,000 miles and I have yet to figure out why. Other than that, it purrs like a kitten and it ran great until the other day. I put a can of seafoam in my full gas tank and ran it out. Then added a fresh full tank of 93 gasoline. Then the next day it started misfiring and stumbling terribly! It normally idles at about 1,000 RPM but right now its idling around 500 RPM and I have noticed an EXTREME loss of power. I hooked my code reader up to it and the only code its throwing is P0172 (Bank 1 System Too Rich) which it has been throwing that code for about 6 months or longer. Could an O2 sensor be causing my car to run so poorly? I have checked the fuel injectors and they are all opening and closing and I don't think the fuel filter could be clogged since it was replaced recently. Im not sure what is causing this rough idle and sudden drop in power. It did this same thing a few months ago and it fixed itself and i didnt have any problems for a while so I'm assuming it is an electrical problem because a mechanical problem wouldnt fix itself. However if anyone has any ideas please let me know! Thank you in advance and happy holidays!
 
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nbk13nw

Member
Mar 31, 2005
186
4
19
60
Newport News, Va
I have an 05 GT and it was running poor for quite a while. Low idle... running rich. .. sounded as if it was cammed. Cleaned the throttle body and everything cleared up. Been running fine since that time.
 

Amber Midkiff

Member
Sep 6, 2015
23
1
13
24
West Virginia
Okay! Thank you! I'm definitely going to try that. I'm going to replace the O2 Sensors, Spark Plugs, and Coils, and clean the throttle body and hopefully that will take care of it!
 

Pantera2013

Member
Sep 29, 2015
126
5
18
25
Kansas
too much cleaner is accually bad for your fuel injectors and can rot them out faster. id only use cleaner once in six months to a year.
 

Pantera2013

Member
Sep 29, 2015
126
5
18
25
Kansas
id try the throttlebody cleaning first cuz its cheap, then if it doesnt do the trick it might be a fuel injection issue
 
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