Running lean problem
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Running lean problem
2002 ford f-150 4.2 automatic 2w drive 100,000 miles.
I’ve searched for the last two days and can’t find what it could be. Hope someone can help.
Engine was running fine but giving me 171, 174 and then 1151 codes. So I searched and everyone was saying o2 sensor, maf and the like. Then I see were someone says isolator bolts will give that code.
So I do the isolator bolts. Everything goes fine till I start it up, No power missing. So I think (this is where things go wrong, me thinking) maybe I crossed a couple of plug wires. So I swap 2 on the driver side, drive it a block and burn up the cat on the driver side (not the plug wires). Replaced cats and o2 sensor, still no power and pinging knocking in exhaust under load. Checked all vacuum hoses. No cel yet but can’t drive or run to long. Plenum
When I did the isolator bolts and Plenum gasket I cleaned the intake with carb cleaner and compressed air. Could I have screwed up the injectors blowing past the butterflies? If no vac leaks what would make it run lean and no power?
I’ve searched for the last two days and can’t find what it could be. Hope someone can help.
Engine was running fine but giving me 171, 174 and then 1151 codes. So I searched and everyone was saying o2 sensor, maf and the like. Then I see were someone says isolator bolts will give that code.
So I do the isolator bolts. Everything goes fine till I start it up, No power missing. So I think (this is where things go wrong, me thinking) maybe I crossed a couple of plug wires. So I swap 2 on the driver side, drive it a block and burn up the cat on the driver side (not the plug wires). Replaced cats and o2 sensor, still no power and pinging knocking in exhaust under load. Checked all vacuum hoses. No cel yet but can’t drive or run to long. Plenum
When I did the isolator bolts and Plenum gasket I cleaned the intake with carb cleaner and compressed air. Could I have screwed up the injectors blowing past the butterflies? If no vac leaks what would make it run lean and no power?
Lead Driver
Joined: Sep 2006
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First, for everyone; you cannot swap plug wires on a guessing game basis and run the motor any length of time without raw gas being passed through the cylinders that don't fire, to the cats where it will burn, overheating the cat/s and distroying it/them.
Id the proper fire order and wire to it.
Next, see what the codes are telling you about what basisc system is in fault and work from that basis only.
Code 171/174 are both banks telling you the fuel tables are shifted to far to the rich side.
Code 1151 is also a code for OX sensor lack of switching on bank 2.
Find the fault and all the codes will clear.
Faults can be air leak into the intake from rotted or hard cracked hoses.
Leaking injector , low fuel pressure, leaking fuel regulator etc.
Basicly anything the can cause the OX sensos to detect an abnormal condition in the exhaust gas flow.
Good luck.
Id the proper fire order and wire to it.
Next, see what the codes are telling you about what basisc system is in fault and work from that basis only.
Code 171/174 are both banks telling you the fuel tables are shifted to far to the rich side.
Code 1151 is also a code for OX sensor lack of switching on bank 2.
Find the fault and all the codes will clear.
Faults can be air leak into the intake from rotted or hard cracked hoses.
Leaking injector , low fuel pressure, leaking fuel regulator etc.
Basicly anything the can cause the OX sensos to detect an abnormal condition in the exhaust gas flow.
Good luck.
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