Flex Fuel Engine problems
Thread Starter
Joined: 11-21-2023
Posts: 4
From: San Diego, CA
Flex Fuel Engine problems
Hello E1, I recently acquired a 2009 Chevy HHR LT . Car has been great for almost 2 years. Well maintained by previous owners. Time to smog and I get a check engine light. On advice from a friend I used Seafoam High Mileage fuel additive to see if that would clear things up and fix the problem. I filled the tank 100% and added 16oz of the product as called out in the instructions. Now I have multiple codes car is stumbling and idle fluctuates when in D. Not sure if this caused the problem or not. I am fairly knowledgeable when it comes to cars and have wrenched on quite a few but one thing I have learned is that if aint broke dont fix it. Need some guidance and direction in here with diagnosis. Thanks in advance...Rick
Engine 2.2L Ecotec Flex Fuel
CODES. p0171, p0300, p0134, p2a00
Engine 2.2L Ecotec Flex Fuel
CODES. p0171, p0300, p0134, p2a00
Moderator
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
Something is wrong with the #1 O2 sensor, that is the one closet to the engine.; Either wires or the sensor. If you replace it avoid Bosch, NGK/NTK are good.
Have you used any silicone around the intake.
Are you using lots of oil?
Are you using lots of coolant?
If any of those is true, fix it before you waste any money.
Have you used any silicone around the intake.
Are you using lots of oil?
Are you using lots of coolant?
If any of those is true, fix it before you waste any money.
Administrator
Joined: 10-13-2011
Posts: 40,082
From: Welland,Ont Canada
Welcome to the site A code P0171 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak downstream of the MAF sensor Possible cracked vacuum or PCV line/connection Faulty or stuck open PCV valve Failed or faulty oxygen sensor (bank 1, sensor 1) Sticking/plugged or failed fuel injector Low fuel pressure (possible plugged/dirty fuel filter!) Exhaust leak between engine and first oxygen sensor
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include: Clean the MAF sensor. Consult your service manual for its location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect all vacuum and PCV hoses, replace/repair as required Inspect all hoses and connections in the air intake system Inspect and/or test the intake manifold gaskets for leakage Check for proper fuel pressure Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool If you have access, you may want to run a smoke test
A code P0134 may mean that one or more of the following has happened: Bad O2 (oxygen) sensor Bad heater circuit in the O2 sensor Wiring or connector to the sensor frayed / broken Blown heater circuit fuse Holes in the exhaust system
The most common fix is to replace the oxygen sensor. But that doesn't rule out the possibility of: Rusted exhaust pipe Inspect wiring & connector(s) for problems Excessive amperage blowing heater fuse (still requires replacement of sensor but also replacement of blown fuse)
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include: Clean the MAF sensor. Consult your service manual for its location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect all vacuum and PCV hoses, replace/repair as required Inspect all hoses and connections in the air intake system Inspect and/or test the intake manifold gaskets for leakage Check for proper fuel pressure Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool If you have access, you may want to run a smoke test
A code P0134 may mean that one or more of the following has happened: Bad O2 (oxygen) sensor Bad heater circuit in the O2 sensor Wiring or connector to the sensor frayed / broken Blown heater circuit fuse Holes in the exhaust system
The most common fix is to replace the oxygen sensor. But that doesn't rule out the possibility of: Rusted exhaust pipe Inspect wiring & connector(s) for problems Excessive amperage blowing heater fuse (still requires replacement of sensor but also replacement of blown fuse)
to the forums!
Thread Starter
Joined: 11-21-2023
Posts: 4
From: San Diego, CA
I am on a budget ( I live in San Diego lol). So I have decided to clean the MAF, inspect and replace air filter these are low cost and cant hurt. Interesting point about coolant and oil. I did the first oil change and coolant flush and fill and read about the sensitivities of coolant level. But recently a friend was driving the car on a hot day and told me he added oil/coolant because he thought it was overheating. I will look into that first. Also In doing some research I came across information about flex fuel GM vehicles and high alcohol content reported due to filling or lack of filling up the tank during refuel. This causing Fuel Trim values to get skewed. The car does need spark plugs according to records,( 137,000 miles) any recommendations on brands, BTW I do have access to higher end scan tool.. Thanks to all
Moderator
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
It would be totally free to look at the wires.
All of those suggestions are good except they ignore the 2 O2 sensor codes. Which is the cause of the P0171.
There is a VIN decoder under "tools" on the tool bar at the top of this page. In 2009 models V means 2.4L, B means 2.2L. I don't know where you got D or P.
Don't let friends take care of your car. Have YOU looked at the oil and coolant? What was the temperature that this friend thought was over heating? Directions for checking them are in the Owner Manual (link in my sig).
Why would anyone blindly add oil if they thought the engine was over heating?
The reason I asked about oil and coolant and silicone is that they can foul O2 sensors. Fairly easy and cheap to replace the O2 sensor, if you can change the air filter. Around $50 at Autozo0ne, borrow the tool from them.
All of those suggestions are good except they ignore the 2 O2 sensor codes. Which is the cause of the P0171.
There is a VIN decoder under "tools" on the tool bar at the top of this page. In 2009 models V means 2.4L, B means 2.2L. I don't know where you got D or P.
Don't let friends take care of your car. Have YOU looked at the oil and coolant? What was the temperature that this friend thought was over heating? Directions for checking them are in the Owner Manual (link in my sig).
Why would anyone blindly add oil if they thought the engine was over heating?
The reason I asked about oil and coolant and silicone is that they can foul O2 sensors. Fairly easy and cheap to replace the O2 sensor, if you can change the air filter. Around $50 at Autozo0ne, borrow the tool from them.
Administrator
Joined: 10-13-2011
Posts: 40,082
From: Welland,Ont Canada
