2005 Buick Lesabre Not Passing Emissions. Help or Ideas needed.

[10thmountain]

SO I have a 2005 Buick Lesabre

Its not passing Emissions.

Throwing code P0171. ( system running lean)Bank 1.

I cleaned the Mass Air Flow Sensor with MAF Cleaner.

Sprayed it like a son of a gun .No go.

PCV ? Maybe? Replace?

O2 Sensor?

Vacuum Hose?

Anyone have this happen on the GM V6 3800 Engines?

 

[ATLDude]

Could be as simple as a vacuum leak, sucking in too much air. I'd check around for loose, rotted or split hoses.

Good luck

 

[boxer90]

In my experience with GM's, it has always been something stupid like an engine coolant temperature sensor or O2 sensor or something silly like that.

When I had my 1997 Saturn S-Class years ago, I replaced that stupid engine sensor three different times.

 

[10thmountain]

I will be searching for Vacuum leaks tomorrow and replacing the O2 Sensor. PCV is easy as well. And its like $3. lol.

 

[Lockout]

Maf has never worked for me
Gm cars I always look at the rubber intake boot for cracks ,splits and make sure air box tight and secure
You can measure maf readings determine bad or good

I have replaced tons on gm cars and pigtails

 

[Buckeye76]

What's an emissions test???

 

[Lockout]

Don't throw parts at it save money get it diagnosed

 

[Lockout]

Could be low fuel pressure which gm is known for bad pumps

 

[coach482]

3.8? Check upper intake. The plastic will rot on underside and create vacuum leak.

 

[Wallace's]

I had the exact code on my sisters Sunfire. I noticed here airbox was cracked/busted. We replaced it and the O2 sensor (I think it was $65) and got the CEL to go away.

May not be the same for you car, but just something to check.