Haunting CEL

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Dec 8, 2007 | 12:32 PM

5. Slow

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From: Northern Illinois

Haunting CEL

Hi everybody,
My truck is a '96 F150 4x4 302 with 120,000. I have had troubles with my CEL coming on for the past two years. First time I threw a code for my O2 sensors. I changed both of those out, and what a pain in the *** it was changing the one on the passenger side manifold. CEL came off and no problems. About six months ago CEL came on again. Ran the code for egr valve flow insufficient. So I cleaned in out twice because the CEL came back on. So now I ran codes again. But I'm no longer throwing the egr code, instead I'm throwing PO1400, PO171 and PO174!!

This truck is starting to drive me nuts. It's been well taken care for and trouble free since I bought it will 50,000 5 years ago. Please help me get this CEL off.

Jim

Dec 8, 2007 | 01:14 PM

danr1

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From: Sand Lake, MI

P0140 02 Sensor Circuit No Activity Detected Bank 1 Sensor 2
P0171 System Too Lean Bank 1
P0174 System Too Lean Bank 2

I guess I'd start with a fuel pressure check and find find out why no No Activity is Detected Bank 1 Sensor 2, may just need a new sensor.

Did you watch the reading from that sensor while it was running with the scanner connected? If so what did it show?

Dec 8, 2007 | 02:53 PM

5. Slow

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From: Northern Illinois

Dan,
This may sound like a stupid question, but how do I do a fuel pressure test?

Dec 8, 2007 | 03:05 PM

danr1

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From: Sand Lake, MI

Quote:

Originally Posted by 5. Slow

Dan,
This may sound like a stupid question, but how do I do a fuel pressure test?

Not stupid at all, you can buy a gauge to do it, may not be cheap, I have not priced one yet and when I asked for one they didn't have one.

I just had mine checked, at the auto parts I was at that also does repair work and had them check mine.

There is a valve on the fuel rail the gauge connects to, looks like a tires air valve.

The gauge the guy used on mine looked very expensive for a "do it yourselfer".

Dec 16, 2007 | 10:05 AM

5. Slow

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From: Northern Illinois

I found a buddy of mine with a fuel pressure gauge and we checked the fuel pressure. It reads 30 psi. That seems about normal right? Any other suggestions to this problem?
Jim

Dec 16, 2007 | 11:08 AM

5. Slow

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From: Northern Illinois

Even though the O2 sensors were replaced, could they have gone bad? I would find that hard to believe but is it possible. How about the fuel filter? I changed it out 2 years ago, would that help the lean fuel problem?

Dec 16, 2007 | 11:14 AM

ameritaz3038

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From: Lockport, NY

i had P0171 and P0174
when i checked my pressure i was at 30 also, a few monthes later guess Fuel Pump took a dump completely
after replacement it clear my code in about 15 miles.

I only repalced one pump but both where shot.

Last edited by ameritaz3038; Dec 16, 2007 at 11:15 AM. Reason: add info