Check engine/Codes
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Check engine/Codes
42HEGO HO2s Sensor voltage high/ system rich
33 EGR fault not closing properly
My check engine came on today and i got the system okay on KOEO but i ran a KOER and got 42 and 33 My egr valve has no vaccum going to it anymore so that could be it but i was really wondering what could be causing 42 the happen this is on a 89 F250 351 C6
33 EGR fault not closing properly
My check engine came on today and i got the system okay on KOEO but i ran a KOER and got 42 and 33 My egr valve has no vaccum going to it anymore so that could be it but i was really wondering what could be causing 42 the happen this is on a 89 F250 351 C6
Fleet Owner
Joined: Oct 2005
Posts: 20,783
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From: Kentucky
DTC 33 indicates the EGR opening is not detected. That would make sense, you state there is no vacuum going to it.
Not sure what is causing the DTC 42. How old is the HEGO? Have you pulled it out to inspect it?
Not sure what is causing the DTC 42. How old is the HEGO? Have you pulled it out to inspect it?
Fleet Owner
Joined: Oct 2005
Posts: 20,783
Likes: 1,749
From: Kentucky
Next questions: Does your truck use oil? If it does the oil can contaminate the O2 sensor. Pull the vacuum hose off the fuel pressure regulator, check it for signs of a ruptured diaphragm by smelling the end of the hose.
How old are the plugs, wires, cap/rotor? Have you pulled the plugs and checked for signs of misfiring/fouling?
How old are the plugs, wires, cap/rotor? Have you pulled the plugs and checked for signs of misfiring/fouling?
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it uses about a quart every 3000 miles, the plugs are new the wires are about a year old the truck runs pretty good most of the time but sometimes it will start idling rough then it will stop and run good after a couple minutes. The truck does not smoke
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Fleet Owner
Joined: Oct 2005
Posts: 20,783
Likes: 1,749
From: Kentucky
That answers the oil consumption question. That leaves the FPR check and pulling the plugs to look for signs of fouling/misfire. You might also consider checking what the fuel pressure is with and without the vacuum hose attached.
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