Emissions Question…

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BigDog9721

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I’m not sure if this all related or not… so here it is. I took my 05 Tahoe in for an emissions test and it failed. The guy told me that resetting my system with my OBD2 scanner messed up my emissions data. He told me to drive the car 10 or so miles and it should reset emissions data and it should pass.
Also, when filling up my gas tank the gas spews out. I have to very slowly put gas in. I have since replaced my EVAP canister filter and solenoid and it still kicks gas back. So gas tank pressure is still wonky So, does the gas tank spewing back be the reason for failed emissions or are they 2 separate issues?
Thanks in advance
 
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Teamiez

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I’m not sure if this all related or not… so here it is. I took my 05 Tahoe in for an emissions test and it failed. The guy told me that resetting my system with my OBD2 scanner messed up my emissions data. He told me to drive the car 10 or so miles and it should reset emissions data and it should pass.
Also, when filling up my gas tank the gas spews out. I have to very slowly put gas in. I have since replaced my EVAP canister filter and solenoid and it still kicks gas back. So gas tank pressure is still wonky So, does the gas tank spewing back be the reason for failed emissions or are they 2 separate issues
Thanks in advance
It might fail or not be able to pass if the computers are not reset at time of inspection, maybe check the line that goes to the canister? They can become clogged at times which would not help the situation.
 

Bill 1960

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Some emissions checks require multiple operating cycles to change state. When you reset codes the state of those checks is set to ”incomplete“. Basically there’s 3 states; pass, fail, incomplete. So now you have to complete the drive cycle for the test in question to update the status.

The requirements for an individual component system drive cycle are usually listed in the service manual.

Failures in the fuel tank venting system are a common source of emission test failure and the MIL light coming on.
 

George B

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Check your state regs. Usually you can have one monitor incomplete. The EVAP will be the hardest to complete and it sounds like there is an issue anyway. Dis you recently unhook the battery? Did you recently clear a code with youe scanner? What was the code?
 

Fless

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I have since replaced my EVAP canister filter and solenoid and it still kicks gas back.

Which solenoid did you replace? The purge valve on the engine, or the canister vent valve up and behind the fuel tank?

When you replaced your canister were there any charcoal bits coming out of it or the evap lines?
 

swathdiver

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I’m not sure if this all related or not… so here it is. I took my 05 Tahoe in for an emissions test and it failed. The guy told me that resetting my system with my OBD2 scanner messed up my emissions data. He told me to drive the car 10 or so miles and it should reset emissions data and it should pass.
Also, when filling up my gas tank the gas spews out. I have to very slowly put gas in. I have since replaced my EVAP canister filter and solenoid and it still kicks gas back. So gas tank pressure is still wonky So, does the gas tank spewing back be the reason for failed emissions or are they 2 separate issues?
Thanks in advance
Time to move!
 
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BigDog9721

BigDog9721

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Thank you guys for all of your input... so here's what happened... Yesterday I took the Tahoe on a 30 mile drive braking stopping and at different speeds.. This morning I took it to emissions and it PASSED! Fuel tank issue was still there... so that didn't cause the emissions failure, it was probably the OBD2 reset and incomplete status. On the way home I stopped by a Jiffy Lube and the guys there seemed to know it was the air valve tube near the gas cap. They cut it, blew it out and that did the job. A $20 tip was well worth it in this case. I also figured I needed front and rear differential fluids topped up as well. It's nice when you are able to get things accomplished with success!
 

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