Check Engine Light Codes Help

[Biggs]

I need the green screen help with some troubleshooting before I get gouged by the mechanics up here in North Dakota. I've got a 2003 Tahoe that's spitting codes P0101- mass air flow sensor, P0171- Bank 1 O2 sensor, P0174- Bank 2 O2 sensor, and P0300- random misfires.

I'm leaning towards the mass flow being dirty? Maybe both O2 sensors went out?

Your thoughts?

[doppelganger]

MAS cleaner is cheap, O2 sensors are fairly inexpensive (looks to be about $40'ish for your vehicle), those two fixes could fix P0300...also, what do your plugs look like?

[Tx.Fisher]

I have an 06 silverado and changed out my mass air flo sensor for about $70, my check engine light went off and my engine ran smoother after I changed it. It's located by your air filter and takes about 5 minutes to change out.

[Biggs]

MAS cleaner is cheap, O2 sensors are fairly inexpensive (looks to be about $40'ish for your vehicle), those two fixes could fix P0300...also, what do your plugs look like?

I just got a can of cleaner. Going to try it first. I havent pulled any plugs yet.

I have an 06 silverado and changed out my mass air flo sensor for about $70, my check engine light went off and my engine ran smoother after I changed it. It's located by your air filter and takes about 5 minutes to change out.

It seemed easy to replace... I watched some YouTube videos

[miket]

I need the green screen help with some troubleshooting before I get gouged by the mechanics up here in North Dakota. I've got a 2003 Tahoe that's spitting codes P0101- mass air flow sensor, P0171- Bank 1 O2 sensor, P0174- Bank 2 O2 sensor, and P0300- random misfires.

I'm leaning towards the mass flow being dirty? Maybe both O2 sensors went out?

Your thoughts?

Look up "intake manifold leaking" or something to that effect. There was an issue with rough idles and high rpm at startup and codes like that, especially when cold, on GM trucks and tahoes with the 5.3l. There is a new gasket that is supposed to fix it.

[Biggs]

Look up "intake manifold leaking" or something to that effect. There was an issue with rough idles and high rpm at startup and codes like that, especially when cold, on GM trucks and tahoes with the 5.3l. There is a new gasket that is supposed to fix it.

I'll do some reading

[Raypo]

The most expensive thing to do is for sure to guess. Without driving it and/or symptoms I can be very little help. A mass air flow sensor can surely cause all those codes along with severe or mild runabiliy problems. An oxygen sensor most likely won't cause cylinder misfire codes. Most likely repair: mass air, plugs, and clean all plenum passages and fuel injectors

[Biggs]

Look up "intake manifold leaking" or something to that effect. There was an issue with rough idles and high rpm at startup and codes like that, especially when cold, on GM trucks and tahoes with the 5.3l. There is a new gasket that is supposed to fix it.

I did some reading and this seems to fit the symptoms.

[miket]

I did some reading and this seems to fit the symptoms.

When mine did it I gently tightened all of the intake manifold bolts and the symptoms were immediately reduced, and no more codes. BUT I still have a slightly high idle at startup when cold outside ( but not as high ). It clearly made the gasket leak less but it is still leaking and Im going to replace it soon. It might be worth it to try the same thing to confirm. Just don't over tighten em.

[Shiner]

Yes, see those codes all the time and it will most always be intake gaskets............ PROVIDING, you have 50 psi fuel pressure minimum. Low fuel pressure will set these too. If FP is good, pull intake

[GarrettM]

When you get ready to clean the MAF remember that the tiny wire is VERY fragile. Spray it with the cleaner and you can LIGHTLY wipe it with a Q tip but usually just spraying it real good will solve it. It will idle high at first after you cleaned it the relearn within a minute or two.

[Biggs]

Yes, see those codes all the time and it will most always be intake gaskets............ PROVIDING, you have 50 psi fuel pressure minimum. Low fuel pressure will set these too. If FP is good, pull intake

I hope so! Just quoted $367 for 3.5 hrs labor
plus parts. Seem reasonable? OEM ACDelco part is $116 or the FelPro at $56...? I've heard the new OEM are good but the FelPro are still better??

When you get ready to clean the MAF remember that the tiny wire is VERY fragile. Spray it with the cleaner and you can LIGHTLY wipe it with a Q tip but usually just spraying it real good will solve it. It will idle high at first after you cleaned it the relearn within a minute or two.

Will do. Thanks

[Biggs]

Getting the intake gasket installed today. Hopefully it works!

[miket]

Getting the intake gasket installed today. Hopefully it works!

I hope so, too! Did you try tightening the intake bolts a little to see of it helps?

[Speedgoat]

I no longer have problems with my '08, because I sold it