Hey guys, I have a 2001 Chevy Blazer with about 134,000 miles on it. Today it started pulling a P0171 as well as a P0174 code. I don't want to jump to conclusions and go out and buy parts to fix it myself so maybe one of you nice people can help..here's what I know.
I've know for about 30,000 miles or so that I've had a exhaust leak ( maybe the manifold bolts ) on both sides, on the passenger side you can see dark soot. I feel like this is why it's pulling these codes. Can someone please tell me if this is the case or not. Or if there is anything I should worry about having these codes on because they come back after I reset them.
I'll take all the help I can get.
Thank you!

 

PO171 SYSTEM TOO LEAN(Bank 1)
PO174 SYSTEM TOO LEAN(Bank2)
When`s the last time you changed your O2 SENSORS?
It seems the exhaust leak maybe the culprit.A complete fuel burn isn`t being registered
by the o2 sensors.

 

I've owned it since 90K and I haven't ever replaced them. I also noticed that the pcv valve, pipe and boot rattle really bad.
How hard/expensive are o2 sensors? And this code just barley came up and I've had the exhaust leak forever.

 

I`ve changed both o2 sensors last summer.It`s not that hard to tackle.My o2 sensors where fairly easy to get too.I think I used a 15 mm wrench to take off and put back on.Or you can buy the special socket that takes off the sensors.The driver side was the easiest.It like right there in front of you.Passenger side is a little tricky but can be done.If you`ve had your ride since the 90K.I would change out the sensors.I had the same both codes before I replaced both o2 sensors.After I replaced them,cleared the codes never came back on eversince.Their normally right around $30.00

 

Hey Thanks!
Do you know what the pipe connecting to the pcv valve is called? As well as the boot ?

 

Not really sure what it`s called.I would contact GMPartsPros.net this is a chevy dealer I buy from in Arizona.Or you caN contact LCM TRUCKS.COM

 

What position o2 sensors do I need? My auto parts store has 3 I'm not sure which ones to purchase.

 

(1) Heated Oxygen Sensors (HO2S) Bank 1 Sensor 2
(2) Heated Oxygen Sensors (HO2S) Bank 1 Sensor 1
(3) Heated Oxygen Sensors (HO2S) Bank 2 Sensor 1

 

I bought mine from summit racing.com Looked up the one`s for 2001 ls blazer 4.3.Their both the same whether it`s bank 1 or bank 2.I bought the bosch brand.Another thing don`t put in gas additives when you fill up.

 

I was thinking the same way as you.Their both the same no matter what position.I bought mine from summit racing.I just looked up 2001 Ls chevy blazer 4.3 v/6 both of them fit the same.I`ve changed mine out last summer.Didn`t take that long to do.You should just need 2/ one on the driver side.You can see it almost even with oil pan bolt.The passenger side is a little tricky but it can be done.If I can do it,,you can do it.