Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
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how does the truck run ?
Ok BIll I think you may have 2 problems here but hard to tell right now
the 171 is a lean code and can be caused by a vacuum leak or low fuel pressure or possibly the MAF sensor
the 452 and 453 codes I would address first
both those codes are saying the fuel tank pressure sensor is reading wrong
and will trigger those codes
you need to unplug the sensor as seen here and with the key on testing on the terminals of the connector you unplugged see if the GREY wire shows 5 volts if it does then see if the BLACK is a good ground
if you have both and the DARKGREEN wire looks good visually replacing the tank sensor should correct the 2 codes
then I would clear the codes and see if the 171 comes back if the 171 comes back a scan tool will need to be connected to the truck and see which O2 sensor is triggering the code and go after a lean condition for that bank,fuel pressure or vacuum leaks
# XXXXX in this picture
ok bank 1 is the drivers side bank of cylinders
the odds are that O2 sensor is bad as long as there are no lower intake vacuum leaks on that side of the engine
I sent pictures of the sensor.it is popped into the top of your fuel pump module top of the fuel tank