Engine Misfiring - Running Rough - new technician

[jacob shedd]

Hey all i'm new to the forum and new to troubleshooting vehicles. I have a 2000 5.4L 4x4 Expedition and am having engine problems. Back around September when i got the vehicle it ran rough so i replaced all sparkplugs and two coils (not sure why i didn't do them all) and it was a day and night difference. Back in November i noticed a clicking noise that happened only when accelerating, when i came back from the holidays it ceased. About 1 week ago when coming back from work i noticed a sudden change in my vehicles preformance - it is "chugging" and sputtering when idle and has trouble accelerating with an emphasis on incline. I do know that two of my coils cannot completely secure due to previous owner stripping the bolt that holds the coils secure. I also have an exhaust leak but i will post a separate post to tackle the problem. The car is very old and fragile (325k+ miles) but i believe with elbow grease and preventative maintenance i can get a couple years worth out of her. My question is this - Based on the information should i replace all injectors/ignition coils/ and spark plugs and hope it solves the problem or should i troubleshoot other alternatives?

Thanks,
Jacob

Edit - Went to Autozone to plug into the computer for error codes (do not know the name of the device) and - to my begotten luck - I have an electrical problem with the output and could not receive any codes.

Edit - After a long day i got codes:

p0171- fuel system too lean (cylinder bank 1)
p0141 HOS2-12 (bank 1 sensor 2) heater circuit malfunction
p0161 HO2S-22 (bank 2 sensor 2_ heater curcuit malfunction
p1131 lack of ho2s-11 switching, ho2s signal low input
p1744 TCC system mechanically stuck in off position
p0174 fuel system too lean (cylinder bank 2)

First thing i did was troubleshoot p0171 which took me to the PCV Cylinder - completely melted and clogged. Replaced and my idle is as smooth as a dream. Still running rough but i do notice a difference. I am going to replace all 4 of the oxygen sensors and try to fix my exhaust leak by replacing the donut gasket between the exhaust manifold and catalytic converter (i just cant find the size of the donut gasket). I have no idea where to start for error P1744. Based off of this do any of you suggest replacing sparkplugs/ignition coils and injectors still? i still feel that my engine is misfiring. Thanks all.

 

[docraymund]

Do a cylinder balance test to identify which cylinder is misfiring. As for the TCC, you might need to change the converter itself.

 

[Bedrck47]

Before you replace all of the O2 sensors you should repair or fix any problems with the codes that are up stream of the O2 sensors P0171 and P0174 it is most likely that these code can be causing the O2 sensor codes.

Read the attached links for some good troubleshooting information

http://www.expeditionforum.com/threads/about-egr-pcv-dpff-evap-iat-tps-maf.23583/

http://troubleshootmyvehicle.com/ford/4.6L-5.4L/troubleshooting-p0171-and-p0174-page-1

 

[1955moose]

As I posted earlier your Exaust donut shouldn't be that big a deal. Your parts store should be able to send you home with the one you need. If in doubt, have them give you the two or three possibilities, return what you don't use. Don't even mess with online places on simple cheap price parts, it's too aggravating when they don't fit. As far as changing coils, No change the boots that go from coils to spark plugs, all 8, unless the two coils you've changed are new. Injectors are probably worn with that mileage, but fix all the other items first. At 325 k miles, your on borrowed time, but you still could go another 100k or so, sounds like previous owner took good care of internals. Keep us posted how the repairs go, and if you get stuck. Moose.


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[Berrye]

A few blasts of Mass Air Flow Sensor cleaner cleared my P0171 and P0174 codes.