Fuel system monitor will not show ready
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,001
Likes: 81
From: Lake Havasu, AZ.
Fuel system monitor will not show ready
So my 2013 Z06, stock except a Akra cat back, just will not set the fuel system monitor to ready so I can get the car smogged. Evap will also not set, but being in Cali. I can have that one show not ready. Fuel system must show ready to pass smog.I have replaced the fuel cap, battery, fresh fuel multiple times, to no avail. Keep car between 1/3-3/4 tank, have ran the specific GM drive cycle at least 8 times from cold start as best as possible, will not set.
No mil, no codes, no pending, no stored, nothing to tell what is wrong. Car is bone stock except cat back.
Someone advised me that it is likely the evap purging not allowing the fuel system to cycle, and therefore will not show ready. But could not tell me why or how to diagnose. Or where to start. Any ideas ?
No mil, no codes, no pending, no stored, nothing to tell what is wrong. Car is bone stock except cat back.
Someone advised me that it is likely the evap purging not allowing the fuel system to cycle, and therefore will not show ready. But could not tell me why or how to diagnose. Or where to start. Any ideas ?
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So my 2013 Z06, stock except a Akra cat back, just will not set the fuel system monitor to ready so I can get the car smogged. Evap will also not set, but being in Cali. I can have that one show not ready. Fuel system must show ready to pass smog.I have replaced the fuel cap, battery, fresh fuel multiple times, to no avail. Keep car between 1/3-3/4 tank, have ran the specific GM drive cycle at least 8 times from cold start as best as possible, will not set.
No mil, no codes, no pending, no stored, nothing to tell what is wrong. Car is bone stock except cat back.
Someone advised me that it is likely the evap purging not allowing the fuel system to cycle, and therefore will not show ready. But could not tell me why or how to diagnose. Or where to start. Any ideas ?
No mil, no codes, no pending, no stored, nothing to tell what is wrong. Car is bone stock except cat back.
Someone advised me that it is likely the evap purging not allowing the fuel system to cycle, and therefore will not show ready. But could not tell me why or how to diagnose. Or where to start. Any ideas ?
Drifting
Joined: Feb 2005
Posts: 1,468
Likes: 174
From: San Jose Ca
Can that be used to tell the catalyst monitor to start? I'm having the same problem with my 2000 gmc sierra. I've tried multiple times to get it to start by driving over 65 for 3+ miles and doing a coast down without brakes to under 20 mph.
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Yeah, everything can be made to instantly show as ready by tweaking the tune.
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Drifting
Joined: Feb 2005
Posts: 1,468
Likes: 174
From: San Jose Ca
Thanks for the reply. thats a little far but if I get desperate..... Looked up the drive cycle criteria for GM. It says I may have to do up to five drive cycles before the catalyst monitor runs. Is a drive cycle considered startup from cold? Also, my fuel level sensor has almost never worked and sits at zero at startup and slowly arrives at the correct level as I drive. Does the catalyst monitor care about startup fuel level?
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,001
Likes: 81
From: Lake Havasu, AZ.
No do not. Being in Cali., the concern is if I set the monitor to ready using HP tuners, this State's Smog will pick that up and fail my car, aaprently it "sees" the tune or changes..... This is from a reputable Vette shop in the area.
He did not say it positively would, just that they are getting better at seeing these changes. Then you fail for tampering and have to go to a referee, no bueno.....
I do not want to use HP tuners unless I know the smog ***** here can not tell I have done so.....
I just went and bought a new evap purge valve, (cheap) and going to see what that does. got a tip that if that goes awry it can cause the fuel system check to never start/complete, and not show codes or pending ......
He did not say it positively would, just that they are getting better at seeing these changes. Then you fail for tampering and have to go to a referee, no bueno.....
I do not want to use HP tuners unless I know the smog ***** here can not tell I have done so.....
I just went and bought a new evap purge valve, (cheap) and going to see what that does. got a tip that if that goes awry it can cause the fuel system check to never start/complete, and not show codes or pending ......
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Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
No do not. Being in Cali., the concern is if I set the monitor to ready using HP tuners, this State's Smog will pick that up and fail my car, aaprently it "sees" the tune or changes..... This is from a reputable Vette shop in the area.
He did not say it positively would, just that they are getting better at seeing these changes. Then you fail for tampering and have to go to a referee, no bueno.....
I do not want to use HP tuners unless I know the smog ***** here can not tell I have done so.....
I just went and bought a new evap purge valve, (cheap) and going to see what that does. got a tip that if that goes awry it can cause the fuel system check to never start/complete, and not show codes or pending ......
Purge valve is “normally closed” so if stuck open when after filling up your gas tank the engine vacuum will draw in fuel vapors from the canister so the car will now be running rich...after all the fumes have been burned in the combustion process the car will run lean due to a vacuum leak !!...has the car been running OK ?... might be a good idea to check the wiring before replacing the solenoid and maybe save yourself some money !!
Last edited by C5 Diag; Sep 14, 2018 at 07:30 PM.
Safety Car
Joined: Nov 2007
Posts: 4,446
Likes: 878
From: Bay Area CA
No do not. Being in Cali., the concern is if I set the monitor to ready using HP tuners, this State's Smog will pick that up and fail my car, aaprently it "sees" the tune or changes..... This is from a reputable Vette shop in the area.
He did not say it positively would, just that they are getting better at seeing these changes. Then you fail for tampering and have to go to a referee, no bueno.....
I do not want to use HP tuners unless I know the smog ***** here can not tell I have done so.....
I just went and bought a new evap purge valve, (cheap) and going to see what that does. got a tip that if that goes awry it can cause the fuel system check to never start/complete, and not show codes or pending ......
As others have said, with HPtuners you can set the monitors "no error reporting" and that should do the trick. However, I know that might also be changing in the near future where they can detect changes in the tune. It is only going to get tougher, but I don't think we are there yet. Good luck.
Drifting
Joined: Feb 2005
Posts: 1,468
Likes: 174
From: San Jose Ca
Yeah I’m not looking for a tune of any kind. The truck is completely stock. I have a feeling that all the monitors got reset when I changed the battery last year. Either that, or they got reset when I cleared the code for my stuck shift solenoid in the valve body.
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No do not. Being in Cali., the concern is if I set the monitor to ready using HP tuners, this State's Smog will pick that up and fail my car, aaprently it "sees" the tune or changes..... This is from a reputable Vette shop in the area.
He did not say it positively would, just that they are getting better at seeing these changes. Then you fail for tampering and have to go to a referee, no bueno.....
I do not want to use HP tuners unless I know the smog ***** here can not tell I have done so.....
I just went and bought a new evap purge valve, (cheap) and going to see what that does. got a tip that if that goes awry it can cause the fuel system check to never start/complete, and not show codes or pending ......
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,001
Likes: 81
From: Lake Havasu, AZ.
Update: Replaced purge valve, disconnected battery overnight, drove 2 drive cycles, all monitors set to ready except evap !
Not sure if new valve, reboot, or long highway drive, or all of them...did it, but it is fine now.
Not sure if new valve, reboot, or long highway drive, or all of them...did it, but it is fine now.
Instructor
Joined: Nov 2018
Posts: 142
Likes: 100
From: SonomaCounty
Fuel monitor and smog
I just picked up my new to me 2013 C6Z and was having the same problem. Fuel monitor wouldn’t set, and I put almost 500 miles of different driving to get it to set to no avail. Went to local chevrolet dealer parts and picked up a new fuel purge vale and put it in. Monitor now reads ok and it passed smog so I can get my CA plates. The car had no codes either. Hope this will help someone else down the road!
Intermediate
Joined: Sep 2021
Posts: 34
Likes: 18
From: Palmdale, Ca
I just picked up my new to me 2013 C6Z and was having the same problem. Fuel monitor wouldn’t set, and I put almost 500 miles of different driving to get it to set to no avail. Went to local chevrolet dealer parts and picked up a new fuel purge vale and put it in. Monitor now reads ok and it passed smog so I can get my CA plates. The car had no codes either. Hope this will help someone else down the road!
Last edited by taps65; Today at 12:57 AM.