Hello!!
my HHR 2006 now I have a issues, when I put the car in neutral I notice the rpm increase, for example if the rpm is in 1500rpm in neutral increase until 2,000 rpm or 2,500 rpm, when I apply the pedal brake firm then the rpm decrease until 950 rpm or 1000 rpm, in that way I notice the consumption gas is a little hight 12.5 litter /100 km, so I am looking for any recommendation, also I saw the light engine is up with the code P0171(System too lean Bank 1) but that is from time to time... any help, Thanks so much

 

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

A good clue, this could be a dirty MAF sensor, loose or unplugged MAF sensor or an exhaust leak between the head and the 1st O2 sensor, if your 2006 has the O2 sensor in the exhaust manifold remove the heat shield and look for a crack in the exhaust manifold, if the O2 sensor is in the exhaust pipe just before the catalytic converter, inspect the flex pipe for cracks

 

The heat shield has been removed, see the O2 sensor in the manifold and the crack in the manifold

 

If it is a cracked flex pipe

https://www.chevyhhr.net/forums/how-...ex-pipe-31536/

 

If you are looking at the DIC "INSTantaneous" for gas consumption, that is just that second not average over time. If you are consuming gas and not moving the MPG is distorted.

 

The 2006 model year didn’t have instant fuel mileage just average for the tankful or since the last time the DIC was zeroed out.

 

yes his has two sensors one under the heat shield manifold and the other in the exhaust pipe, as I always said " thanks so much"

 

Are you sure it’s the gear and not depressing the clutch that causes the decrease in RPM?

 

You might try disconnecting the negative battery for 30 minutes, to give the computers a reset.

 

hi Oldblue if the crack is in the manifold, what can I do? replace or is possible to weld?, thanks