Time for injectors stock or 30 overs?

04chase

Member
Mar 28, 2008
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Noticed injector 4 nearing +6% on hot idle in gear . No noticeable negative performance or excess haze.


Mods currently are stock engine with the basic bolt ons
Intake/turbo back exhaust
Manifolds
Fass 165 /sumped and shimmed rail
Danville 3794 stg 2
Stock injectors
Stock engine 125k
Mike l trans with goerend t.c.


I'm considering a 30 over set of injectors, but in Cali I need to smog it with a 100 %stock tune . I need to know if it will run decent without a tune(how bad ) and if it will set any lights



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2004LB7

Well-known member
Dec 15, 2010
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I wouldn't do anything until you actually have symptoms of failing injectors. then as said above do 60%. 30 is basically no change from stock so a waste of money. 60s and a clean tune will get you through smog
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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I agree that you should go larger, but I'm not going so far as to say they make "basically no change". A good tune can make 60's have stock power with no smoke and keep the necessary OBD2 requirements
 

04chase

Member
Mar 28, 2008
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Ok some of you may not know calis new rules.

The factory tune has to be in. Nothing changed at all, not even tire size.

They now check for oem software cal i.d. in the ecm. So if all components still pass but the #s don't match the stock calibration , it fails. No ways around this either.

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gmduramax

Shits broke
Jun 12, 2008
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Ok some of you may not know calis new rules.

The factory tune has to be in. Nothing changed at all, not even tire size.

They now check for oem software cal i.d. in the ecm. So if all components still pass but the #s don't match the stock calibration , it fails. No ways around this either.

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You don’t know what they actually check, I live in California.
 

2004LB7

Well-known member
Dec 15, 2010
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he's probably referring to the tunes checksum. if anything in the tune is altered from stock then the checksum will change. California had a proposal to use the checksum as a way to tell if someone was running a modified tune. this checksum was crosschecked with a list from the manufacturer. if it didn't match you failed. from my understanding it was never implemented. I live in California and have not failed from having modified calibrations. last smog check I got was in July of 2021
 
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04chase

Member
Mar 28, 2008
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he's probably referring to the tunes checksum. if anything in the tune is altered from stock then the checksum will change. California had a proposal to use the checksum as a way to tell if someone was running a modified tune. this checksum was crosschecked with a list from the manufacturer. if it didn't match you failed. from my understanding it was never implemented. I live in California and have not failed from having modified calibrations. last smog check I got was in July of 2021
Exactly what I'm referring to.


Started just after your smog it would appear.


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THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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Exactly what I'm referring to.


Started just after your smog it would appear.


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he's probably referring to the tunes checksum. if anything in the tune is altered from stock then the checksum will change. California had a proposal to use the checksum as a way to tell if someone was running a modified tune. this checksum was crosschecked with a list from the manufacturer. if it didn't match you failed. from my understanding it was never implemented. I live in California and have not failed from having modified calibrations. last smog check I got was in July of 2021
Yup, they now check the checksums. They have been checking the OS numbers for years which is why trucks with a dsp5 would fail as it changed the OS#, but they stepped it up this year. It has caused issues with swapped trucks as the tune file present must exactly match the truck your swap came from. So guys are getting smogged with non working gauges and such now to get through, then flashing in the working tune after inspection.
 

2004LB7

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Dec 15, 2010
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Yup, they now check the checksums. They have been checking the OS numbers for years which is why trucks with a dsp5 would fail as it changed the OS#, but they stepped it up this year. It has caused issues with swapped trucks as the tune file present must exactly match the truck your swap came from. So guys are getting smogged with non working gauges and such now to get through, then flashing in the working tune after inspection.
how are they getting around the CEL bulb check if the gauge doesn't work? that would normally be an instant fail in California.
 

gmduramax

Shits broke
Jun 12, 2008
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Exactly what I'm referring to.


Started just after your smog it would appear.


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Yup, they now check the checksums. They have been checking the OS numbers for years which is why trucks with a dsp5 would fail as it changed the OS#, but they stepped it up this year. It has caused issues with swapped trucks as the tune file present must exactly match the truck your swap came from. So guys are getting smogged with non working gauges and such now to get through, then flashing in the working tune after inspection.
I haven’t had any tuned trucks fail yet, but that’s with the correct vin, OS, calibration. Even after august. But this is on emissions equipped trucks of course.
 

1FastBrick

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Dec 1, 2016
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Despite what is being published. They can not possibly review each and every smog inspection file. The New testing protocol takes a snap shot of the calibrations present.

But, If the place you use gets caught . They will send you a letter and you will have to re smog the vehicle. and when that time comes. It better have the correct OS and corresponding CVN's to the calibrations....

Now that being said, I know some one with a DSP5 tune that passed in California with the correct emissions equipment intact.

I recently met some one with a basically stock Gas truck that re geared it and put an approved cold air intake on. He first stated the Vin did not match during the inspection. When I looked at his paper work for the "failed smog" it indicated it did not have a correct calibration. The notes were hand written and something was circled. Thats when more details were given and he explained he had to visit a state referee. I was shown the tune file and the Vin was correct to the paper work and the truck. I looked up the calibration for his vehicle on the Tis web site and that were I was able to show him CVN was not correct for the operating system on his truck. I told him to see if a dealer can get a modified calibration for his truck with correct gear ratio for what installed. I know there is a way they can do it legally through GM if it was an optional gear ratio. The biggest problem is finding some one that will take the time to do it.

I suspect the shop he used was caught tampering and he was issued to have it inspected by a state referee. They are the only ones that will take the time to verify the calibration and the matching CVN. Your typical smog guy doesn't see or look at that information during the inspection process.

If there are no visual red flags and it meets the requirements of the OBDII scan performed during test, it should pass.
 
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04chase

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Mar 28, 2008
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How would .030 overs run in a truck with a stock tune? Besides being fuel heavy would the truck trip a light?

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Eddie_LLY

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Jul 28, 2014
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How would .030 overs run in a truck with a stock tune? Besides being fuel heavy would the truck trip a light?

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Your question is exactly mine. I am in a state with rules exactly like OP and I need to play by the rules. About to do a head gasket job at Wade Boyd and I’d like to come out the other side with as much could be done performance wise while still fully (getting bent) to the rules.
Thanks for any input, I know my restrictions make helping hard on this kind of form.


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Eddie_LLY

Member
Jul 28, 2014
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I’ve got a built transmission with Evans 1078 is that helps sorry I forgot to add it


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TheBac

Why do I keep doing this?
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Apr 19, 2008
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Talk to Wade about it. He will know far more about your build and how to stay "within the rules" in Colorado than most of us would. He's not going to send you down the wrong path.