Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
how many miles is on it?
does the engine light stay on?if so,can you give me the computer codes?
does the engine ever die out on you?
does it always start good cold?
what all have you tried?
please explain your problem to me the best you can
230k miles on it, I replaced the fuel pump last year, i replaced the fuel pressure regulator 2-3 months ago, check engine light is on and there is two codes p0420 and p0430. Truck starts great cold never cuts out has plenty of power. I have a hypertech power programmer on it. I have replaced sensor 1 bank 1 and sensor 2 bank 2. and the coolant temp sensor. Last week i rechagred air filter, cleaned MAF, and changed fuel filter. When truck gets up to running temp and is shut off and it is restarted within 15- 20 minutes of shutdown it will start without a problem. If it sits for longer then 20 minutes or so I have to pump the gas pedal to get it to start on the first try. Or i can let it turn over for 30 seconds until it finally starts.
the first thing to do here is to check the fuel pressure,these must have no less than 55psi at all times.test it when it wont start,just to make sure it isn't loosing pressure when it get s hot..............but,this sounds as if you may have a bad crank sensor,these will do this sometimes when they go bad,and not give a code for it...when these are breaking down with heat like this,testing the crank sensor may not help,,,replace it...the codes you are getting makes me think the catalyst converter may be bad,but,i don't think it is why the engine is not starting
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CONDITIONS FOR RUNNING THE DTC
CONDITIONS FOR SETTING THE DTC The PCM determines the oxygen storage capability of the catalytic converter has degraded below a calibrated threshold.ACTION TAKEN WHEN THE DTC SETS
CONDITIONS FOR CLEARING THE MIL/DTC
TEST DESCRIPTION The number below refers to the step number on the diagnostic table.
REMOVAL PROCEDURE CAUTION: Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components. IMPORTANT: Perform the CKP System Variation Learn Procedure when the crankshaft position sensor is removed or replaced.
If this doesnt work how can i get back in touch with you?
yes,i will leave it open
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