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2002 Ford Expedition Repair Question


Topics covered: Heater, Engine, Blend door.
Mileage: 150,000 miles.

Asked on December 9, 2012

Ford Expedition Heater Problem

Check engine light came on after turning on the heater codes says it is banks 1 an 2 running lean
Avatar Asked by richardtaylor

Answer

Replied on December 9, 2012

I need the exact code numbers and engine size?

Tiny Answered by saturntech9 (expert)
23,174 answers provided
Replied on December 9, 2012

5.4L an the code were p0171 an p0174

Tiny Response from richardtaylor
1 question asked
Replied on December 9, 2012

Have you checked for a vacuum leak yet?Thats where i would start.

Tiny Answered by saturntech9 (expert)
23,174 answers provided

Replied on December 9, 2012

yea we ran a smoke test did everything plugs fuel filter cuz it was doing it before with out the turning on the heater but last week it did it again hen we turned the heat on so i cleared the codes to make sure an right when we turned it on again it did it ive never heard of a heater makin it throw lean codes

Tiny Response from richardtaylor
1 question asked
Replied on December 10, 2012

Have you thought of maybe one of vacuum actuators are leaking vacuum causing the code when vacuum is applied or the hose to it?Thats all i can think of with the symptoms you are describing.So when you move the temp control all the way to max hot it triggers the code?

Tiny Answered by saturntech9 (expert)
23,174 answers provided
Replied on December 10, 2012

no that i did think of ill try that thanks for ur help

Tiny Response from richardtaylor
1 question asked

Replied on December 10, 2012

It looks like you may have a vacuum controled heater control valve look at the hoses going to your heater core see if there is one there?If there is one use a hand vacuum pump to see if it holds vacuum?

Tiny Answered by saturntech9 (expert)
23,174 answers provided
Replied on December 10, 2012

Looks like your blend door is not powered by vacuum.

Tiny Answered by saturntech9 (expert)
23,174 answers provided
Replied on December 10, 2012

really its mechanical ?

Tiny Response from richardtaylor
1 question asked
Replied on December 10, 2012

just to add, there is a vacuum elbow behind the throttle body on the pcv line that is common for collapsing and causing the lean codes

Roy

Tiny Answered by ASEMaster6371 (expert)
24,845 answers provided