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Can you turn off the rear o2 sensors and pass CA smog?
There is a TSB for early c6 z06 cars that triggers the check engine light for the rear o2 sensors. Dealer wants $160 to update the software per the TSB but I could just as easily disable the rear o2s in HP tuners. Will turning off the rear o2s lead to failing the OBD2 smog check?
There is a TSB for early c6 z06 cars that triggers the check engine light for the rear o2 sensors. Dealer wants $160 to update the software per the TSB but I could just as easily disable the rear o2s in HP tuners. Will turning off the rear o2s lead to failing the OBD2 smog check?
should pass without any issues as long as the sensors are there and hooked up for the visual with no CEL's.mine are in place and turned off in the tune and our smog check mirrors California's
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by ssbowtie1
There is a TSB for early c6 z06 cars that triggers the check engine light for the rear o2 sensors. Dealer wants $160 to update the software per the TSB but I could just as easily disable the rear o2s in HP tuners. Will turning off the rear o2s lead to failing the OBD2 smog check?
If it's done properly you can pass the OBDII test without 02 sensors or even cats for that matter.
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by ssbowtie1
Can you elaborate on what you mean by "done properly"?
In the Engine Diagnostics section, anything relating to the OBDII checks (EVAP, O2 sensors, EGR etc) all have to be set to SES Enable and 3-No Error Reported. After having done that all the systems that the smog test checks for will show immediately as ready - none of the BS drive cycle is required.
I would also set the Cat overtemp protection system to read "no" in your fuel tables
AND in the diagnostic section also set the diagnostic testing for the cats to read "disabled" in the tables reading ----- Catalyst testing----Post 02 testing---and Closed loop testing---
I am saying the exact same thing but just as an extra precaution turning OFF the diagnostic testing as I describe just takes it one step further to ensure no problems This is using EFILIVE--perhaps HP has no access to delete ALL cat testing procedures
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by tblu92
I am saying the exact same thing but just as an extra precaution turning OFF the diagnostic testing as I describe just takes it one step further to ensure no problems This is using EFILIVE--perhaps HP has no access to delete ALL cat testing procedures
The additional steps aren't needed. I've probably helped people with this at least 20 times and it always works as expected.
There is a TSB for early c6 z06 cars that triggers the check engine light for the rear o2 sensors. Dealer wants $160 to update the software per the TSB but I could just as easily disable the rear o2s in HP tuners. Will turning off the rear o2s lead to failing the OBD2 smog check?
Something like a VX Gm nano will run you about $100, TDS 2 year subscription for SPS programming will run you $40, and when you are done after the firmware flash upgrade yourself, will have a tool to run both Tech2 win, and GDS2 software for repairs yourself.
If you don't want a nano or Tech II to have yourself for repairs, then find someone that does have one around you, pay the $40 for a TDS subscription for 2 years, and have them flash in the firmware upgrade yourself.
Bottom line, your not going to get through a Star inspection with modules like the rear 02 sensors turned off instead.
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by Dano523
Bottom line, your not going to get through a Star inspection with modules like the rear 02 sensors turned off instead.
Sure you will, I've done it with my car and have shown several other people how to do it. Hell, I don't even have cats or O2 sensors in my car and it still passed.
In the Engine Diagnostics section, anything relating to the OBDII checks (EVAP, O2 sensors, EGR etc) all have to be set to SES Enable and 3-No Error Reported. After having done that all the systems that the smog test checks for will show immediately as ready - none of the BS drive cycle is required.
Thank you for that!
Hmm...this is making me think again about installing headers. I didn't realize it's that easy to pass the OBD II test.
In California, if your car is registered in an area which requires a biannual smog check, don't believe what you read here about being able to pass with headers and no cats.
It's virtually impossible nowadays, because of the fines the State levies on smog inspectors who "look the other way" when doing the visual check.
In fact, even headers with cats is a no-go unless the headers have a CARB EO number.
For offroad or experimentation purposes, you can disable DTCs P0420 and P0430–the two cat efficiency codes–by using the procedure discussed earlier. That way you can leave the sensors in place and have the catalyst monitor I/M flag set to "yes".
02-27-2018, 11:24 AM
Can you turn off the rear o2 sensors and pass CA smog?
