Code 171 and 174
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Code 171 and 174
Sorry if this has already been shown. Model year 2000 F150 with 4.2 liter 6 cylinder triggers Service Engine Soon lamp and OBD II tester shows codes 171 and 174.
Found deteriorated and leaking U shaped vacuum hose on left rear (pass side) of engine near firewall. The engine did not idle rough. You can't see the back of the hose but laying on the engine you can reach around and feel the softness.
For now, replaced the hose with about 8 inches of 3/8 ID fuel line for $1.29
BTW a decent OBD II tester by Autel for $15 from Amazon
Here is the offending hose.
Found deteriorated and leaking U shaped vacuum hose on left rear (pass side) of engine near firewall. The engine did not idle rough. You can't see the back of the hose but laying on the engine you can reach around and feel the softness.
For now, replaced the hose with about 8 inches of 3/8 ID fuel line for $1.29
BTW a decent OBD II tester by Autel for $15 from Amazon
Here is the offending hose.
