Mechanics

HAD CODES P0171 AND P0174

2001 Chevrolet Suburban • 136,000 miles

I also had codes p0171 and p0174 so I looked at the intake gaskets and replaced them, also a few vacuum line elbows that I found cracked that went from the fuel pressure regulator to the air intake. And those codes have not come back.
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Thomasstuckey
October 2, 2012.




102 is a mass air flow code. The 400 series are evap codes.

How does it run?

Are all connections good at the mass air flow? Is the big hose to the air filter tight and secure?

Roy

With the MAF connected it would start fine then about 10 to 15 seconds the RPM's would decrease and it sounded like it was ready to stall but really just run rough. The air filter intake hose is secure the connection look good, i've got good PWR in 14VDC and a solid ground, from the signal side with the truck running I get about 5.04VDC. I didn't get the 400 series codes until I changed the MAF. When I disconnect the MAF it runs perfect with no issues.

Tiny
Thomasstuckey
Oct 2, 2012.
Most likely the sensor is bad.

Roy

So you think that the new sensor I put was just bad?
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Tiny
Thomasstuckey
Oct 2, 2012.
Possible. Why did you replace it

Roy

Because I got the 102 code after replacing the intake gaskets for codes 171 and 174.

Tiny
Thomasstuckey
Oct 2, 2012.
Did you try the old mass air flow? Since you replaced the gaskets, the sensor may not have been bad, just unable to overcome the vacuum leak

Roy

I changed the MAF after taking care of the other elbows and gasket

Tiny
Thomasstuckey
Oct 2, 2012.
Ok, did you put the old one back on?

Roy

Nope I did a one for one so no $65 core charge

Tiny
Thomasstuckey
Oct 3, 2012.

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