I have a 2009 hhr. It starts right up then dies. I'm at wits ends. OK. Here we go. I
changed the fuel pump, plugs, coils, cam sensors, map sensors, o2sensors,
intake manifold. It will stay running if you keep pumping the gas it fluctuates
between 2000 and 5000 rpm. Still throwing codes: p0101, p0171., p0101p,
p0171, and p0300 please help.
Edit:
Well I'm back at it, I changed the EVAP next to the engine, no help. Checked all vaccuume lines all good. Checked the wire harness and all plugs, all good. So back to square one. HELP
Edit:6/21
Son took for a long ride after clearing codes the only one that came back and stayed was P0101
I am attaching some screenshots he sent

 

Make sure the connector is plugged in on air filter above throttle body. Let's tackle P0171 first, check for vaccum leaks, cracked flex pipe, clean MAF sensor. It could be a bad 02 sensor, but not likely, but worth sticking your head under the car to make sure it did not get broken ...yes my son managed to break his off. Borrow a fuel pressure gauge from the parts store and check your fuel rail pressure.

 

It could also be a bad fuel injector or clogged up air filter.

 

What engine size?

 

1. The plug is good, air filter is new, both 02 sensor are new cannot hear a vaccum leak where is the MAF sensor??

 

Mass Air Flow Sensor. Mak esure it is plugged in and no pins got bent. There is mas air flow sensor spray cleaner, do not use wd40, gasoline or any other substitutes. https://howtune.com/articles/87-chan...hhr/image-1092

 

Except for the flex pipe, you won't be able to hear a vaccum leak.

 

fuel pressure?

 

2.2 flex fuel there is a new Map sensor thanks for the help

 

MAP sensor is on the intake manifold, MAF sensor is on the air tube from the air filter box to the rubber elbow to the throttle body.

P0101 points to the MAF

https://www.obd-codes.com/p0101

and so does the P0171 code

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

Notice both mention wiring connections, double check the connector for dirt, bent pins and corrosion