Question about 2007 Chevrolet Trailblazer

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2007 trailblazer with po171 Code

My Trailblazer is throwing a po171 code when it is cold out. The code comes and goes. The vehicle will start and miss once or twice then it runs fine. the colder it is the worse it gets. Cleaned the throttle body, changed the MAF sensor, Checked the air box. Is there a way to tighten the intake manifold in case the gasket is loose and not have to take it all apart to replace it if there is a leak? Any help would be appreciated. Thanks

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  • 1,632 Answers

Check all vacuum hoses , replace air filter with new one .

Posted on Jan 23, 2013


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Posted on Jan 02, 2017

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SOURCE: my 2003 chevy trailblazer keeps throwing code

change thermostat

Posted on Jun 06, 2009

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SOURCE: O2 check engine light

U may indeed have a faulty MAF or O2 sensor, the way to tell if the MAF or a vacuum leak is at issue is that both O2's will code lean, if only one codes lean then it is most likely just a faulty O2 sensor, I don't have your codes but this is the way we do things at the dealer for problems like yours. Remember the O2's are before the Cat's., after the Cat's they are called Cat efficiency monitors in the book.

Posted on Jan 03, 2009

  • 17 Answers

SOURCE: I cant find out what is causing these lean codes on bank 1 &2.

vacuum leek,bad computer or you have a linkage out of adjustment on the throttle body

Posted on Feb 23, 2009

  • 4 Answers

SOURCE: Service engine soon light flashing on acceleration

When the service engine soon light is flashing there is a miss fire in the motor if you look in your owners manual it will tell you that.The same thing happend to me and it endid up to be the cat...

Posted on Mar 17, 2009

  • 543 Answers

SOURCE: Code 171 Bank 1 too lean

well actually you cant clean the mass air flow,you usually ruin it when you clean it,it could be a bad maf or just crapy gas,not crappy enuff that the car doesnt run,but enuff it doesnt like the air/fuel mixture and is setting the light

Posted on Oct 10, 2009

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2001 GMC Sierra 5.3 check engine light Po171

with the engine cold spray the intake manifold near the gasket with the carb cleaner see if the idle changes if it does replace the gasket

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Chrysler Crossfire will crank but not start. It starts fine when it's cold, but after driving around or making multiple stops, it will not start again. I have already changed the fuel pump relay

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I have a 2006 Trailblazer. When it is cold outside the check engine light comes on. The code is P0171. But all summer and when temp is above 40 it goes out and stays out til the next cold day then comes...

Code P0171 is a lean oxygen sensor code for bank 1 on your engine. Bank 1 is always the side of the engine where #1 cylider is located.

There are a couple of Technical Service Bulletins (TSB's) that may apply to your problem.

Bulletin No.: 09-06-03-004C
This bulletin covers intermittent problems due to oxidation problems in some of the wiring connectors.

Bulletin No.: 03-06-04-030G
This bulletin outlines repair proceedures for clogged or restricted fuel injectors.

The only other thing I can think of would be a vacuum leak that occurs only in cold ambient temperatures and only affects bank 1. (possible intake manifold gasket or something similar.)

Dec 19, 2010 | 2006 Chevrolet Trailblazer

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My engine light is on , when i drive it acts like it wants to stall, also the temp. gage goes to 210

190-210 degrees is normal operating temperature for TB's (yes they run hot). If it goes past that, then we have a problem. Most likely that would be the thermostat ($25). That engine light is throwing a code that we can diagnose, bring the TB into Autozone or someone that will scan your vehicle for free. Need to find out what code it's pulling up on the scanner. We can help from there once the code is known.

Dec 11, 2010 | 2006 Chevrolet Trailblazer

1 Answer

Missing at cold start both codes po171 and po174 runs ok on the road and after warmup stops missing

year make and model would help a lot.

P0171 and P0174 are lean codes. Since it is running rough at start up and goes away when warm it is usually a sign that the plenum gaskets are leaking. If this is a pickup with a 5.3 liter than for sure the intake plenum gaskets that go in between the intake and the heads are leaking. Very common problem. Once the engine warms up everything expands and the leak seals itself up.

If you can post the year make model and engine size I can help you out a little more.

Nov 28, 2010 | Chevrolet Tahoe Cars & Trucks

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What could cause code PO128 to come up on a 2002 Chevy Trailblazer

Sounds like the thermostat may be stuck open or has anyone put a colder thermostat in the car,because once it starts to get cold it will throw a SES with a colder then stock thermostat.

Code PO128; coolant temp below thermostat regulating temp. Replace the thermostat and that should address your issue.

Thank you for using fixya and good uck

Sep 01, 2010 | 2002 Chevrolet TrailBlazer

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I just replaced the intake and right head gasket on a 98 expedition 4x4 5.4l and now the vehicle has a miss when driving with light acceleration betweeen 35-55mph. this is a dead miss but you can't...

I also have this exact truck and I am a drivability technician.
First if you have a dead miss check for waht code is stored. Even if the light is off a code should still be stored. Once you know what cylinder is missing you can rotate the coil and and see if the miss follows by checking codes again. Do the same for the injector even tho this is alot more work. Once you determine that the code always stays on the same cylinder then you can inspect for maybe an intake vacuum leak or if the EGR is close by sometimes a EGR stuck open will miss at low RPMS. Its suppose to be open when cruising so a miss would not occur then.

Why was the engine work done. maybe you didnt fix the pryor problem if you didnt have the head sent out to be inspected and block tested. These engiinee heads are known to fail with cracks thats why it needed to be tested. Hopefully you did this

Dec 01, 2009 | Ford Expedition Cars & Trucks

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Service engine soon light flashing on acceleration

It sounds like u got a coil pack going out. Alot of times when your engine is cold or when you arn't putting a load on it the coils won't fail. How ever when the engine reaches operating temperatures and there is load on the coils that is when they are going to break down. my advice would be to get a scanner and see what cylinder the missfire is at then swwap that coil to another cylinder to verify that the coil is defective. If it is purchase another with a new spark plug put it in and let it rip.

Apr 13, 2009 | 2005 Chevrolet TrailBlazer

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Service engine soon light flashing on acceleration

When the service engine soon light is flashing there is a miss fire in the motor if you look in your owners manual it will tell you that.The same thing happend to me and it endid up to be the cat...

Mar 17, 2009 | 2002 Chevrolet TrailBlazer

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