Mechanics

CHEVY ERRORS P0102, P0171, P0174

2003 Chevrolet Tahoe

Engine Performance problem
2003 Chevy Tahoe V8 Two Wheel Drive Automatic 103k miles

I keep getting errors P0102 MAF/VAF circuit low input, P0171 Bank 1 system too lean, P0174 Bank 1 system too lean. I've found 2 of the oxygen sensors located by the catalytic converter but have no clue where the others are located up towards the engine. Also the car is running rough during cold weather but with warmer weather runs a lot smoother. Any suggestions you can give me would be greatly appreicated.
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Appst8design
April 17, 2008.



Check and make sure you have no vacuum lines off. Also check and make sure you dont have a vacuum leak on your intake manifold gaskets

Tiny
Rhall77
Apr 17, 2008.
What would be the best method about checking for leaks in these areas?

Tiny
Appst8design
Apr 17, 2008.
Look for lines off, you can spry carb cleaner by the gasket area and listen for the rpm to raise, but do it when it is cool, you dont wanna start a fire.

Tiny
Rhall77
Apr 17, 2008.
SO CARB CLEANER BY THE GASKETS ON THE AIR INTAKE MANIFOLD SHOULD DO THE TRICK IN LOOKING FOR LEAKS OR IS THIS FOR ALL VACUUM HOSES?

BY CHANCE DO YOU KNOW WHERE THE O2 SENSORS ARE LOCATED FOR BANK 1 AND 2 ON AN 03 CHEVY TAHOE DO YOU? I FOUND THEM NEXT TO THE CATALYTIC CONVERTER BUT DON'T HAVE A CLUE WHERE THEY WOULD BE ATTACHED IN THE ENGINE. SHOULD THAT BE MY NEXT STEP AFTER CHECKING FOR LEAKS?

THANKS FOR YOUR HELP.

Tiny
Appst8design
Apr 17, 2008.
I wouldnt be putting o2 sensors in it. I am about 90% sure you have a vacuum leak or a maf sensor bad. Check the intake hose by the MAF sensor. See if it is loose. I wouldnt replace parts unless im sure what it is. What kind of air filter do you have in it, what kind of shape is it in. But for your question, the O2 sensors are located in the exhaust pipe by the engine, you just have to look for them and you will see them.

Tiny
Rhall77
Apr 17, 2008.
Mass Air Flow sensor I'm guessing from what I've read on different websites? Where would this be located and what exactly does this sensor look like? Thanks again for all your help.

Tiny
Appst8design
Apr 17, 2008.
By the air filter in the hose going to the engine

Tiny
Rhall77
Apr 17, 2008.
I sprayed all the connections (especially any connections in between the air filter and where it enters the engine) with carb cleaner and didn't hear any fluctuation in RPMS. I also checked the air filter and its brand new since my last oil change (less than 1000 miles on it). I also looked for loose air hoses and was not able to find any. Then I tightened all the hose clamps even more to ensure it wasn't that. So what would your next suggestion be?

MAF would be that part right after the air filter or the part which controls the butterfly valve controling the air entering the engine?

Tiny
Appst8design
Apr 18, 2008.
No its before the throttle body.

Tiny
Rhall77
Apr 18, 2008.


http://www.2carpros.com/forum/automotive_pictures/179747_0417081740_2.jpg



http://www.2carpros.com/forum/automotive_pictures/179747_0417081740a_1.jpg



http://www.2carpros.com/forum/automotive_pictures/179747_0417081741_2.jpg



These are areas I sprayed with carb cleaner. If I don't have an air leak would it be the MAF sensor do you think or an 02 sensor? Is pic number 1 the MAF sensor or the 3 one? Thanks again for all your help.

Tiny
Appst8design
Apr 18, 2008.
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