2003 GMC Sierra Has recently developed rough idle/lope at idle which sometimes goes away. Runs fine otherwise. Scan codes-Lean condition bank1 and bank2. Random misfires on all cylinders. Fuel pressure checks good. Cleaned throttle body and MAF. New air filter/fuel filter. No obvious vacuum leaks. Is it time to start changing ouut sensors in hopes of a fix?

Question 1

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I have an 03' chevy silverado 1500 with only 95,000 miles. It's having a rough idle. It lopes at idle but as soon. As you give it gas it idles fine for a few seconds and then goes back to loping. It runs...

Clean your throttle body and map/maf sensor. If that doesn't work you may have a bad iac sensor (idle air control sensor)

Aug 31, 2017 • Cars & Trucks

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Rough idling/loping at idle it otherwise runs fine off idle.

1. Vacuum leakage Check throttle body and intake manifold for tightness. check all vacuum hoses.
2. Faulty fuel or pump or electrical.
3. Plugged PVC valve.
4. Air filter clogged
5. Leaking head gasket.
6. Camshaft lobs worn.
All of these porblems can cause lopes or erratic idle.

Apr 14, 2011 • 1993 Chevrolet S-10 Blazer

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Codes 171 174 2002 gmc sierra 5.3

Try some injector cleaner in order to see if the lean condition improves. Lean conditions can sometimes be caused by o2 sensors or other sensors that are not within specifications.

Jul 08, 2010 • 2000 GMC Sierra

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My 2003 GMC Sierra idles rough and cut off sometimes when turning.Replaced fuel filter and changed plugs.engine light stays on.Which 02 sensors do i need to replace first? Before converter or after...

Before replacing the O2 sensors, I would check the fuel pressure. You may also try to have someone pull a trouble code from the powertrain control module to verify why the engine light is on. Do not replace any parts until this is done, otherwise your going to be guessing at the root cause, and it will get expensive with part replacement.

May 11, 2010 • 2003 GMC Yukon XL

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I have a 2003 gmc yukon 5.3 the engine idles rough sometimes the idle will get so low the engine will shut off.(the engine runs good while driving) hooked to scaner po101 maf/vaf (dont know what vaf is),...

you have a vacume leak somewhere.check all of your vacume hoses for leaks.Injector seals can cause this too.Also intake gaskets could be leaking.Running to lean usually means the car is getting to much air coming in.To check leaks spray brake cleaner around the hoses and the bottom of your intake if the rpms change then you found a leak.

Feb 21, 2010 • 2003 GMC Yukon XL

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2003 Mazda MPV ES that idles very rough when warm

that means could be vacuum leak

Jan 10, 2010 • 2003 Mazda MPV

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Error codes appeared on 2003 GMC Yukon PO170 too lean bank 1 PO174 tool lean bank 2 PO300 multiple cylinder misfire Still runs OK, idles a bit rough.

Check the intake manifold gaskets for leakage. It will tend to run rougher in the morning when it is cold. Check for vacuum leaks on any hose connected to the intake plenum too.

Dec 13, 2009 • 2003 GMC Yukon

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2003 Tahoe Running rough, Idle irratic, Ck engine light on. I put it on a OBD2 code reader and showed p0101 mass airflow sensor and bank 1 and 2 running lean I cleaned the sensor but still having problem...

Yes, replace the MAF, then check if the lean condition goes away. It should.

MAF's are sensitive to cleaning. Sometimes it works, other times it doesn't.

Dec 11, 2009 • Chevrolet Tahoe Cars & Trucks

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Rough/Low idle then dies.

is your check engine light on any longer ? also has your throttle plate ever been cleaned that can cause this symptom it will get build up on it and not allow correct idle ,you can clean it yourself ,rmove the big hose that goes up that goes up to your throttle body and get a can of deep creep sold at any parts house ,then spray the deep creep on a shop rag and by hand wipe out as much of the flap areas as you can ,its hard to get your fingers in there but be patient . but dont spray any thing down in the throttle throat it may cause more problems ,try the wipout of the throtlle area and see if it help your idle !

Aug 08, 2009 • 2003 GMC Sierra 1500

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2001 Tahoe: Hard to start, idles rough, check engine light on.

Flashing check engine light is missfire, fuel pump probably causing multiple tries to start.Having to build fuel preasure,vac leak on one side of intake probably causing rich/lean condition.Also check back preasure to cat ,Sound like you are moving down right track.Mas air flow would probably set lean code bank1 and lean code bank2

Jun 19, 2009 • 2003 GMC Yukon XL

Question 2

Anonymous

You never replace anything, on a Wishing,Hoping,Pushing,Poking,diagnostic approach

You learn the vehicles Systems,Test,then Replace,if you have a failed component.

Work on the Misfire Issues.
Then you lean O2 Codes will go away.

Not a the plugs.

Think lean---Vacuum leaks,EGR Valve leak,EVAP System leaks,anything with a hose that lets air into the intake system.
Exhaust System leaks,near sensors

phoenixnorth Nov 24, 2010

Can't find a vacuum leak.
Double checked every hose and vacuum connection.
Might need a smoke test?
mkgsrv Dec 29, 2010

A smoke test would probably be a huge help. these engines are notorious for leaks where the intake meets the heads due to warping (underbuilt plastic composite construction). dorman products sell an improved design that is reinforced. hope this helps

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I have an 03' chevy silverado 1500 with only 95,000 miles. It's having a rough idle. It lopes at idle but as soon. As you give it gas it idles fine for a few seconds and then goes back to loping. It runs...

Rough idling/loping at idle it otherwise runs fine off idle.

Codes 171 174 2002 gmc sierra 5.3

My 2003 GMC Sierra idles rough and cut off sometimes when turning.Replaced fuel filter and changed plugs.engine light stays on.Which 02 sensors do i need to replace first? Before converter or after...

I have a 2003 gmc yukon 5.3 the engine idles rough sometimes the idle will get so low the engine will shut off.(the engine runs good while driving) hooked to scaner po101 maf/vaf (dont know what vaf is),...

2003 Mazda MPV ES that idles very rough when warm

Error codes appeared on 2003 GMC Yukon PO170 too lean bank 1 PO174 tool lean bank 2 PO300 multiple cylinder misfire Still runs OK, idles a bit rough.

2003 Tahoe Running rough, Idle irratic, Ck engine light on. I put it on a OBD2 code reader and showed p0101 mass airflow sensor and bank 1 and 2 running lean I cleaned the sensor but still having problem...

Rough/Low idle then dies.

2001 Tahoe: Hard to start, idles rough, check engine light on.

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2003 Sierra 1500

I have an 03' chevy silverado 1500 with only 95,000 miles. It's having a rough idle. It lopes at idle but as soon. As you give it gas it idles fine for a few seconds and then goes back to loping. It runs...

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Related Questions:

I have an 03' chevy silverado 1500 with only 95,000 miles. It's having a rough idle. It lopes at idle but as soon. As you give it gas it idles fine for a few seconds and then goes back to loping. It runs...

Rough idling/loping at idle it otherwise runs fine off idle.

Codes 171 174 2002 gmc sierra 5.3

My 2003 GMC Sierra idles rough and cut off sometimes when turning.Replaced fuel filter and changed plugs.engine light stays on.Which 02 sensors do i need to replace first? Before converter or after...

I have a 2003 gmc yukon 5.3 the engine idles rough sometimes the idle will get so low the engine will shut off.(the engine runs good while driving) hooked to scaner po101 maf/vaf (dont know what vaf is),...

2003 Mazda MPV ES that idles very rough when warm

Error codes appeared on 2003 GMC Yukon PO170 too lean bank 1 PO174 tool lean bank 2 PO300 multiple cylinder misfire Still runs OK, idles a bit rough.

2003 Tahoe Running rough, Idle irratic, Ck engine light on. I put it on a OBD2 code reader and showed p0101 mass airflow sensor and bank 1 and 2 running lean I cleaned the sensor but still having problem...

Rough/Low idle then dies.

2001 Tahoe: Hard to start, idles rough, check engine light on.

Not finding what you are looking for?

2003 Sierra 1500

I have an 03' chevy silverado 1500 with only 95,000 miles. It's having a rough idle. It lopes at idle but as soon. As you give it gas it idles fine for a few seconds and then goes back to loping. It runs...

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