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Need some help . My 09 Z06 keeps getting a po171 lean bank 1 code . Car will run shitty to the point where you can’t even drive it problem is it doesn’t do it all the time . You can drive for a day with no issues and then out of no where po171 code and car will barley run . I replaced the following . Btw Car only has 4,000 miles on it .
-all new GM fuel injectors
- new GM mass air flow sensor
- 2 new GM front o2 sensors
- switched coil packs , wires and plugs from bank 2
- fuel pump pressure at 65 psi and holds steady even when running shitty
- checked battery voltage on battery 12.6 volts
- checked everything for vacuum leaks
- flushed fuel system several times
also before anyone says anything I recently bought the car in July with 3,100 miles on it so I’m not the one who left it set lol . I would love to be driving it before winter hits ...
Last edited by Chris2000ss; Oct 20, 2019 at 07:23 PM.
I looked over the service manual for that code, and you checked or replaced many of the items listed as possible causes.
There are other items that could be causing that DTC as well.
From the service manual, here is a PDF for that code. Maybe it will give you more things to check.
Air leak on the exhaust side before the o2 sensor or a vacuum leak on the intake side are additional things to check for. Get a scan tool and look at the long term adaptive memory values for both banks while the condition is occurring. being a intermittent issue just adds more fun to the diagnosis. Could you describe drives shitty a little better.
Air leak on the exhaust side before the o2 sensor or a vacuum leak on the intake side are additional things to check for. Get a scan tool and look at the long term adaptive memory values for both banks while the condition is occurring. being a intermittent issue just adds more fun to the diagnosis. Could you describe drives shitty a little better.
engine light flashes car misses badly pops out the exhaust. Don’t get any other codes other than the po171. Car will run like this for a little while then run normal...
Last edited by Chris2000ss; Oct 21, 2019 at 08:26 AM.
Reason: Add
With the flashing check engine light you obviously have a misfire on bank 1...so you changed the injectors but they do need power to work...I would check all 4 injector pink wires and make sure you have 12 volts with key on...to check the control side of the circuit since it is ground side switched take a 12 volt test light connected to battery POSITIVE and with the car running probe the other injector wire (striped wire) and the test light will dimly flash...if it does the PCM is properly grounding the circuit !!....I would also check that you have spark at all cylinders on bank 1...again parts were swapped there but you didn’t do any circuit testing I’m presuming ??
With the flashing check engine light you obviously have a misfire on bank 1...so you changed the injectors but they do need power to work...I would check all 4 injector pink wires and make sure you have 12 volts with key on...to check the control side of the circuit since it is ground side switched take a 12 volt test light connected to battery POSITIVE and with the car running probe the other injector wire (striped wire) and the test light will dimly flash...if it does the PCM is properly grounding the circuit !!....I would also check that you have spark at all cylinders on bank 1...again parts were swapped there but you didn’t do any circuit testing I’m presuming ??
injectors were changed with brand new GM . I will do the test you mentioned above . Thanks for the info !
Great !!...50 new injectors will not fix your problem if you don't check the electrical side of the injectors !!..video enclosed of basic injector testing !!
Great !!...50 new injectors will not fix your problem if you don't check the electrical side of the injectors !!..video enclosed of basic injector testing !!
Guys I just figured something out . Injectors are working they should be . The whole bank one is not firing at all . So it’s definitely an electrical issue what controls this ?
GREAT !!...if you did not have spark I was going to tell you to check the coil harness connector that sits in the center of the coil packs for power and ground...I guess you wouldn't have had power there !!...moral of the story..."ALWAYS CHECK POWER AND GROUNDS BEFORE FIRING THE PARTS CANON !!
How I found it was I had the car running and leaned on the fuse panel and it started missing . I took my hand off and it quit . So I started digging found the center harness was loose and needed tightened up
Good find !!...so your P0171 (lean condition) was the result of no spark...with unburned fuel in the combustion chamber one would think..."HEY, I should be seeing a rich condition instead of a lean one"...the answer is NO !!... the O2 sensor does NOT see unburned raw fuel as a rich condition !!
Good find !!...so your P0171 (lean condition) was the result of no spark...with unburned fuel in the combustion chamber one would think..."HEY, I should be seeing a rich condition instead of a lean one"...the answer is NO !!... the O2 sensor does NOT see unburned raw fuel as a rich condition !!
yep that’s all it was . But things like that are hard to find sometimes. I wasn’t getting any misfire codes only the lean code . If I hadn’t leaned on the fuse box I would still be digging lol 😂. Thanks for all the help !!
Last edited by Chris2000ss; Oct 24, 2019 at 05:16 PM.
Good on you for sticking with it and finding the fix. It's great when people post problems and solutions - helps us all learn about and enjoy our cars. Not to mention saving lots of $$$. Thanks for sharing!
Good on you for sticking with it and finding the fix. It's great when people post problems and solutions - helps us all learn about and enjoy our cars. Not to mention saving lots of $$$. Thanks for sharing!
thanks bud ! This should be archived if anyone else has this issue ....
Po171 issues
