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I was hoping I wouldn't have to tune after installing headers and x-pipe (with cats). But, I'm getting these codes now:
P0137
P0157
P0420
P0430
She's complaining about those pesky rear O2 sensors. Like I said, it has cats but are the sensors just too far away creating a voltage drop? There are extenders between them and the original connectors.
Question I have now is which tuner? Diablosport or HPTuners? Which one can program the rears out?
If your rear O2’s are seeing low voltage (less than 450mv’s) coupled with those 2 cat efficiency codes I’d look for an exhaust leak anywhere between the front and rear O2’s since you had exhaust work done…a Shop Vac with the hose switched around and some soapy water will find them…an exhaust leak will drive those rear O2’s low in that area of the exhaust…normally you’ll see 600-800mv’s or so.
The bank 2 sensor is shorted to ground. Check the wiring.
I would think only one of the two would throw codes, it's doubtful both are shorted to ground. I routed and insulated the wires away from anything that would melt or chafe them.
If your rear O2’s are seeing low voltage (less than 450mv’s) coupled with those 2 cat efficiency codes I’d look for an exhaust leak anywhere between the front and rear O2’s since you had exhaust work done…a Shop Vac with the hose switched around and some soapy water will find them…an exhaust leak will drive those rear O2’s low in that area of the exhaust…normally you’ll see 600-800mv’s or so.
Ok, I'll triple check, odd that both of them are throwing those codes.
Ok, I'll triple check, odd that both of them are throwing those codes.
Sounds great !!...I assume you have a scan tool so get the cats nice and hot and see what the downstreams are reading...if they are stuck low disconnect the downstream sensors and check your 450 mv bias voltage...if you see 450mv you DON'T have a wiring issue.
You will not escape the P0420/P0430 efficiency codes with those cats. If you don't want to tune, your best bet to get rid of those two codes is to use the de-gasser inserts for the rear O2's. They sit between the O2 sensor threads and the O2 sensors themselves and they have a very tiny hole in the end to allow a very small amount of exhaust to hit the sensor so that it is functional. Even these can cause slow response codes though but much less likely.
The other 2 codes are low voltage codes. This means the car is running lean, or more so that the O2 thinks it is. Could actually be running lean or more likely you have an exhaust leak from poor fitment, incorrect installation, or leaking manifold gaskets.
You will not escape the P0420/P0430 efficiency codes with those cats. If you don't want to tune, your best bet to get rid of those two codes is to use the de-gasser inserts for the rear O2's. They sit between the O2 sensor threads and the O2 sensors themselves and they have a very tiny hole in the end to allow a very small amount of exhaust to hit the sensor so that it is functional. Even these can cause slow response codes though but much less likely.
Well, that's not very encouraging... but then again, I was pretty much resigned to tuning them out at this point. So, my question there is: which tuning package? I'll most likely use it more than a few times as the years go on. I tuned my ZR-1 several times (the old burn the eeprom routine). Fun times.
you've drastically reduced the physical amount of catalytic converter material in your exhaust. what you have in there now is the bare minimum to make it not terribly stinky, not comply with emissions. either tune it to properly remove the CEL, or go with a half-measure like an o2 spacer and just reset the CEL you'll still get a few times per year.
Well, that's not very encouraging... but then again, I was pretty much resigned to tuning them out at this point. So, my question there is: which tuning package? I'll most likely use it more than a few times as the years go on. I tuned my ZR-1 several times (the old burn the eeprom routine). Fun times.
Tuning these cars is vastly more complex than the old eeprom days. However, you could probably manage to get the O2 DTC corrected with some assistance on HPTuners forum. You just need the MPVI2 or MVPI3 interface and however many ECU credits for your model year. I believe it is 4 credits for 2017+ cars and 2 for 2015-2016. Hiring a remote tuner would get you some power too and fix everything at once.
I went with the HPTuners option and after a mild learning curve (and taking their online course to unlock the emissions settings), I was able to take care of the O2 codes as well as tune the NPP and get rid if CAGS. Nice first steps!
Next is to look into a slightly more aggressive "91 octane" tune. Maybe. It's not like the car is lacking power, at least for the street!
I went with the HPTuners option and after a mild learning curve (and taking their online course to unlock the emissions settings), I was able to take care of the O2 codes as well as tune the NPP and get rid if CAGS. Nice first steps!Next is to look into a slightly more aggressive "91 octane" tune. Maybe. It's not like the car is lacking power, at least for the street!
You live in GA as I do , why are you going to do a slightly more aggressive "91" Octane tune when 93 us available everywhere ? There is not that much to gain in the tune maybe 20 hp so if you are going to tune it , go for 93 . One word of warning I also would not tune without a wideband as tuning the LT series of engines is not as easy as the past motors , there are many parameters you need to know about , one slip up and you will have an expensive paperweight Save yourself time and money and just find someone who will "remote" tune the car for you Dave
I want to start conservative, I mean there's a bit of HP left on the table but for the exact reason you mention, I don't want to screw up! I'm not going to do anything until I wrap my head around torque management and all of the air mappings. I'm gathering just how intertwined all of the mappings are, it's definitely not as easy as advancing timing and watching for knock anymore!! I have a wideband coming, I'll be logging that with HPTuners too.
O2 Sensor codes after header install
would get you some power too and fix everything at once.
