Truck starts and runs great but will suddenly die while driving.

2001 GMC SONOMA
2.2L • 4 CYL • RWD • AUTOMATIC
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DLBUTLER01
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Sometimes it runs great, for weeks at a time even, but sometimes it won't go more than a few miles before it dies without any warning, like it isn't getting any fuel. Always fires right back up. Usually happens when fuel is low, but has happened when full. Had codes pulled, fuel mixture is rich. We have replaced the fuel filter and checked all relays and fuses, fuel lines, vacuum lines, fuel pump does come on and fuel pressure is good. Any suggestions?
Apr 2, 2014 at 2:06 PM
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KNOWLEDGE IS POWER
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If the fuel mixture is Rich that means you have unburned fuel going into the exhaust. That means you're getting plenty of fuel you're just not burning it all. Have you checked your spark plugs and wires, it may be time for a tuneup.
Apr 2, 2014 at 3:40 PM
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DLBUTLER01
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Yes. We have done a complete tune up.
Apr 2, 2014 at 3:45 PM
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KNOWLEDGE IS POWER
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Okay, then it could be that your catalytic converters are losing their efficiency and they are causing the engine computer to lean out the fuel mixture at times causing your engine to shut down. You might also have a fuel injector that's leaking fuel into a combustion chamber when it's not supposed to. Either way I'm sure that the engine computer is shutting down the engine due to a rich fuel mixture
Apr 2, 2014 at 3:51 PM
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DLBUTLER01
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We had the codes pulled again today. We got p0141, p0178, and p0179. We found the HO2S in the manual but the other 2 codes aren't on the list and cannot find anything about the fuel composition sensor in the manual either????
Apr 4, 2014 at 5:15 PM
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The fuel composition sensor is inline in the fuel line on the frame rail. Check it for power at the plug with the key on engine off. If it has power either the sensor is bad or there's wire damage in the harness. Look at the wires for chafes or breaks first. The 02 sensor heater one means the 02 sensor is bad
Apr 4, 2014 at 5:31 PM
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DLBUTLER01
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Thank-you!
Apr 4, 2014 at 6:42 PM
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You're very welcome let me know if I can help some more
Apr 5, 2014 at 6:53 AM