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Keep Getting Lean Conditions

Beebe

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Beebe Enthusiast

Beebe

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2000 Silverado 1500 4X4 Z71 5.3L 156000 miles. I need to pass emisions by the end of the month. I had a code saying the catalitic converters were bad. I planned on changing them, when my power steering pump went out. Scanned the truck for grins, and had the catalyst one and that's all. Changed the pump, cleared codes and the next weekend did the y pipe. After changing the pipe I scanned it and notice not only the catalyst code but a p0171. (lean bank one). Cleared codes drove for 2 days and light comes back. Scanned it and p0171 and p0174. Never had this code until I changed power steering pump. This weekend I needed to change an idler pulley. I noticed the rubber gasket that goes on the intake from the shroud was not seated properly. I thought awesome a simple fix. Reinstalled it cleared codes. I still sprayed ether around intake gasket to see if it surges, and nothing happened. I'm at work and do not know the code yet, but I bet it's is a lean condition again. What the heck is a guy to do?

txab Senior Enthusiast

txab

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Have you checked fuel pressure? Changed fuel filter? Low fuel pressure can cause a lean condition

Beebe Enthusiast

Beebe

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Have you checked fuel pressure? Changed fuel filter? Low fuel pressure can cause a lean condition

 

 

Replaced fuel pump about 2 years ago, and the fuel pressure regulator. The fuel filter is about a year old.

Beebe Enthusiast

Beebe

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More info.

I cleaned out my MAF sensor and reassembled. Cleared codes, and started. No codes yet, but I checked the readings of the MAF sensor.

It was 40 degrees outside, Fuel system was NOT in closed loop. My readings were as follows.

 

MAF (Lb/M) .048-.060

MAP (Hg) 10.00

 

Is this correct? Thanks.

Beebe Enthusiast

Beebe

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intake manifold gaskets. use only felpro gaskets. i had same problem do the intake gaskets problem solved.

 

Shouldn't surge when I sprayed ether around intake?

DanJS10 Enthusiast

DanJS10

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Don't these composite intakes have rubber o-rings to seal the ports against the aluminum head?

Beebe Enthusiast

Beebe

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+1 on intake gaskets

 

20 minute job. change them

 

very hard to find leak with spray

 

just replace them

 

Well I gave up and took it in. You guys were right it was the intake gaskets. Only cost $300 with Felpro gaskets. Thanks for the help all.

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