Emission codes PO171 and PO174 faults

[Paul Albert]

I need to clear these codes in order to pass a nevada smog test
PO171 system too lean bank 1
PO174 system too lean bank 2
The local rover shop is telling me the purge valve could be the problem?
Any ideas on what might be causing the emission codes?
Thanks

 

[douglastic]

I replied in your other thread:

Codes on both banks mean the issue is in some shared component, usually before the fuel is mixed with air.

have you tried cleaning the MAF sensor (or swapping a good one with a buddy to test) or tried cleaning the throttle body and resetting the TB adaptations?

I would at least start there and start eliminating the cheapest/easiest items first.

I had these codes (plus a few others) and my fix was new MAF sensor, new PCV valve, manually clean TB, reset adaptations.

keep in mind that after you have fixed the problem and cleared your codes, you need to complete a proper drive cycle to put the monitors back in the ready state before another smog test. sometimes 100 miles of mixed driving (start, stop, freeway, etc).

 

[Paul Albert]

Ok thanks I will proceed with your suggestions
I will get back with you with my results
Thanks again

 

[Paul Albert]

Cleaned the MAF sensor and put over 50 miles on and so far no engine light
I will put on more miles tomorrow and scan for faults
I will get back with you with the results

 

[Paul Albert]

After cleaning the MAF sensor and driving over 100 miles the PO 171 & 174 faults were cleared and the LR passed the smog test
One hell of a lot cheaper than what the LR shop wanted $1000.00 +/- and they still couldn’t guarantee the smog test
Many thanks for your advice and help

 

[remember5]

Nice. I'm running a can of P44 or whatever they mentioned and have a new MAF sensor. Luckily I'm not due for emissions until February.

 

[Redinak]

God I love living in places with no emissions testing.

 

[remember5]

Filled the tank and added the BG44k cleaner to the tank and cleared codes. Drove to work and the light came back, cleared codes again and drove a few miles and the light came back again. Been driving all week with the light on and am at just over half a tank and when I started yesterday to come home the light went off on it's own. I was amazed because I thought that light was staying on until I manually cleared the codes. We'll see what this weekend holds...