Trouble code p0134 and p0171

How many miles is on this truck?

>100,000 miles?


To save time,please do a combustion block leak test to rule out pin hole head gasket leak.

A shop can do this test in few minutes.

Start monitor for coolant and oil levels.

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Check the O2 sensors wires and make sure they are not damaged or cut.
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If the wiring to O2 looks OK then you are ready for new O2.

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Check and clean the connector of the coolant temperature sensor.

If the dash reading is OFF from the actual thermometer reading then change the coolant temp sensor ASAP.

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EGR leak and carbon blockage can indirectly cause P0171 code.

Cleaning carbon from EGR valve and EGR air passage is a whole day job.

Make sure you has a NEW EGR base gasket before you start.

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