Opinion on if retune necessary - 2003/4 cobra whipple 2.3 reverting from offroad to stock mid pipe

[venomous99]

For smog legality curious if car that was tuned with an off-road was later changed back to the mid pipe will there be any issues running it that way indefinitely? The tune was done with a whipple 2.3, stock manifolds, 13lbs boost , supporting fuel, maf , etc mods. Prefer not having to retune with the stock pipe if possible

 

[2003RedfireVert]

I have never ran my car without all the proper government mandated, environmentally friendly equipment; however, if I had and I needed to put the mandated smog equipment back on (which I have never had to do), I would not retune it IF it was only for the emissions test. Again, this would never apply to me.

Good luck. YMMV.

 

[SsnakeSVT03]

You will need to retune for the stock mid-pipe with cats. Talk to your tuner.

 

[PC03GT]

Without a tune you'd probably kill those meows

 

[01yellercobra]

Maybe the difference for me was going from a catted X to the stock mid pipe, but I never had an issue. The A/F didn't change according to the wideband. I'm sure I gave up some power, but I kept it on for a bit because I was lazy.

 

[decipha]

If tuned properly then it would be perfect fine.

however, they probably turned off the rear o2s and if tuned using a flash device that changes the stock tune you'd fail regardless.

 

[Pribilof]

You'll likely need a new tune. Are your rear O2's turned off? Did they turn off cat over temp protection? If you're trying to SMOG in CA you'll need the stock tune or a CARB approved tune to pass. If you have any other tune you'll get sent to a referee.

 

[venomous99]

You'll likely need a new tune. Are your rear O2's turned off? Did they turn off cat over temp protection? If you're trying to SMOG in CA you'll need the stock tune or a CARB approved tune to pass. If you have any other tune you'll get sent to a referee.

yes, for smog the car stock tune is reloaded along w/ the stock midpipe. drive cycles until monitors are ready.. after smog, would like to just run the car w/ the stock cats so when its smog time its only a matter of reloading the stock tune again. sounds like issue will be depending on how the tune is, one runs the risk of frying the primary cats. probably would be safer for me to just get a catted mid pipe or find a shop to weld in some high flow cats to the existing offroad. that probably wont be as much of a drastic change in backpresure/air flow vs offroad to stock midpipe.

 

[Pribilof]

yes, for smog the car stock tune is reloaded along w/ the stock midpipe. drive cycles until monitors are ready.. after smog, would like to just run the car w/ the stock cats so when its smog time its only a matter of reloading the stock tune again. sounds like issue will be depending on how the tune is, one runs the risk of frying the primary cats. probably would be safer for me to just get a catted mid pipe or find a shop to weld in some high flow cats to the existing offroad. that probably wont be as much of a drastic change in backpresure/air flow vs offroad to stock midpipe.

It's not a backpressure issue... if COT is turned off then you'll melt your cats. Also, you won't pass the visual in CA with aftermarket cats.

 

[decipha]

Anytime you've ever flashed a tune to your ecu and then return it to stock you need to verify its fully returned to a stock production cal. The only way to verify is to use a moates quarterhorse to read the current tune off the ecu and verify it against a stock production cal to make sure only the pats code, VIN and resulting VID block checksums are different. Otherwise it will set a referee if anything else has been changed.

You can do it yourself with TunerPro.

 

[venomous99]

It's not a backpressure issue... if COT is turned off then you'll melt your cats. Also, you won't pass the visual in CA with aftermarket cats.

I don’t intend to smog with afternmarket cats. Gotcha on melting the cats. Won’t run the stock pipe besides for smog

 

[venomous99]

Anytime you've ever flashed a tune to your ecu and then return it to stock you need to verify its fully returned to a stock production cal. The only way to verify is to use a moates quarterhorse to read the current tune off the ecu and verify it against a stock production cal to make sure only the pats code, VIN and resulting VID block checksums are different. Otherwise it will set a referee if anything else has been changed.

You can do it yourself with TunerPro.

Do u know a tuner who can tune with the quarterhorse?
When u read the current stock tune what things are you looking for and how does one compare to a stock production cal? is it lines of code to compare or u looking at some checksum number as a summary? do you know if an SCT xcal when reloading the stock ECU tune will screw up the code that would trigger a flaggable discrepancy?
curious for those that are doing hot smogs how are they able to do that if the vehicle code is not loaded assuming the donor car isnt the exact model ? not advocating a hot smog but just curious about how are ppl able to get by with that. my understanding the smog machines today are pulling hte ecu profile base on model type and they will do a comparison on the ecu code for disrepencies vs known legal ECU stock tunes for that particular model

Anytime you've ever flashed a tune to your ecu and then return it to stock you need to verify its fully returned to a stock production cal. The only way to verify is to use a moates quarterhorse to read the current tune off the ecu and verify it against a stock production cal to make sure only the pats code, VIN and resulting VID block checksums are different. Otherwise it will set a referee if anything else has been changed.

You can do it yourself with TunerPro.

 

[Pribilof]

My understanding of the CA SMOG system is that is looks at the checksum of your tune and compares it to the SMOG database. They do the same thing in Colorado now. People with aftermarket tunes get an error "unable to connect" and then get sent straight to a referee station. -Like what decipha said.

Check this thread:

Anyone help with whipple swap for CA smog.

So I’ve been trying to get some more clarity on whipples EO for the 03-04 cars. As some here may know the CARB EO number for the whipples are for the blowers only. I asked for more clarity on this from whipple as I am considering using a whipple to replace the stock blower. Whipples responses...

www.svtperformance.com

You're not going to get into boost for a SMOG test. Load the factory tune, install your OEM cats, get your monitors to "ready," drive to the test without getting into boost. Pass and go home and put your car back the way you want for the next 2 years.

Also, call Whipple and get the CARB EO sticker before your test.

 

[venomous99]

My understanding of the CA SMOG system is that is looks at the checksum of your tune and compares it to the SMOG database. They do the same thing in Colorado now. People with aftermarket tunes get an error "unable to connect" and then get sent straight to a referee station. -Like what decipha said.

Check this thread:

Anyone help with whipple swap for CA smog.

So I’ve been trying to get some more clarity on whipples EO for the 03-04 cars. As some here may know the CARB EO number for the whipples are for the blowers only. I asked for more clarity on this from whipple as I am considering using a whipple to replace the stock blower. Whipples responses...

www.svtperformance.com

You're not going to get into boost for a SMOG test. Load the factory tune, install your OEM cats, get your monitors to "ready," drive to the test without getting into boost. Pass and go home and put your car back the way you want for the next 2 years.

Also, call Whipple and get the CARB EO sticker before your test.

yes, the car has passed before with the stock ECU tune and midpipe setup so no issue w/ reverting to that temporarily. decided i will add some highflow cats on the existing offroad xpipe for normal driving and will go back to the stocker come smog time every couple years. when i was much younger i could tolerate the offroad exhaust but nowadays i want things to be quieter and not draw the wrong attention from a cop to have reason to pull me over.

 

[decipha]

Anyone can tune with a quarterhorse the software tunerpro is free.

you plug the qh in to the ecu, read the ecu, then load a stock compare file and click compare differences

if more than just the pats code and vin is different then its not a stock file and has been modified and will is not emissions legal.

if you've reverted back to stock before and it passed then no worries you should be fine so long as you didn't change tuning devices.