P0171: System too Lean (Bank 1)

08 HHR started throwing this code.

Any suggestions?

Thanks

 

vacuum leak, cracked flex pipe.

 

Most likely a dirty MAF sensor, but I must ask , which engine! 2.2, 2.4, or 2.0 Turbo ?

Have a read, and clean the MAF with proper spray cleaner specific to the job

https://www.obd-codes.com/p0171

 

08 Chevy HHR 2.2L - 158,00 miles. The code does not seem to affect the driving. Shows up after the 2nd or third trip out typically.

 

Then let’s clean the MAF , disconnect the negative terminal at the battery in the spare tire well first, then clean the MAF .
Reconnect the battery terminal.
Remember the rear lift gate had an electrical release mechanism, so DO NOT close the gate while the battery is disconnected!
Place a folded towel over the latch to prevent accidentally closing it.
Please don’t ask me how I know, just learn from my mistakes.

 

I cleaned the MAF and the P0171 has popped up again.

 

post #2

 

I checked for any leaking and didn't detect anything not sure what the flex pipe is?

 

flex pipe is the flexible part of the exhaust pipe off of the manifold.

What it means is there is unmetered air getting into the system somewhere between the MAF and the #1 O2 sensor. OR tthere is not enough fuel getting pushed into the injectors.

Other things since it is intermittent

EVAP purge valve (the one under the hood) disconnect both hoses and electrical connection, blow into either side. Free flow it's bad. Easy, cheap DIY fix.

Fuel pump, check fuel pressure. Expensive, a good bit of experience needed for DIY.

Either of those may also cause hard starts.

 

If the flex pipe were cracked enough to throw the code your exhaust would be louder and you might smell exhaust fumes in the car. I know I did when mine was cracked but it never threw a code. Is your exhaust louder than usual?