2017 Miata Grand Touring CEL

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JoeA217
Posts: 6
Joined: Tue Sep 08, 2020 10:33 am

2017 Miata Grand Touring CEL

Post by JoeA217 »

Hello,

I have the Roadstersport Super Q, Roadstersport Mid-Pipe, Injen Air Intake, and 1320 Performance Headers. My CEL stays on after starting the car, which was not an issue prior to the upgrades. The codes were P0421 and P0171. 1320 Performance recommended to purchase their angled spacer which I did and installed on the secondary O2 sensor per their instruction. The CEL didn’t stay lit after starting the car and driving it on the freeway, but it eventually came back on the next time I drove the car. The codes I’m getting this time are P2096 and P0137. I was wondering if someone out there is having similar issues and how it got rectified. I greatly appreciate any feedback anyone may have. Otherwise, I am planning on just having my stock headers re-installed and not have to deal with the CEL issue; lest, I have a real engine problem in the future and wouldn’t know that it’s actually a legitimate issue. Thanks so much!

Joe
Brian
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Re: 2017 Miata Grand Touring CEL

Post by Brian »

Hi Joe

Sorry, never heard of that header before. Normally no codes if full header back system installed and the O2 sensors are retained but post header converter sensor is moved to position post the midpipe cat. From what you have written, not clear to me that second sensor is now after midpipe converter?
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
JoeA217
Posts: 6
Joined: Tue Sep 08, 2020 10:33 am

Re: 2017 Miata Grand Touring CEL

Post by JoeA217 »

Hey Brian,

The header came with an O2 sensor mount and it’s about an inch below the four tubes coming down from where it’s mounted on the engine and it’s currently connected. The mid pipe is the part 61-2660 RoadsterSport Premium 304 which I bought from your company. I believe the secondary O2 sensor is at the mid pipe. I’m not sure if this answers your question.

Thanks,
Joe
Brian
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Re: 2017 Miata Grand Touring CEL

Post by Brian »

Where is the second O2....in relation to the converter, before or downstream?
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
JoeA217
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Joined: Tue Sep 08, 2020 10:33 am

Re: 2017 Miata Grand Touring CEL

Post by JoeA217 »

It’s downstream.
Brian
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Re: 2017 Miata Grand Touring CEL

Post by Brian »

Make sure wires exit both O2 sensors without being pinched over at hard angle. The sensors have tiny breathing holes out the back center of each between the wires and will not function correctly if those get covered.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
JoeA217
Posts: 6
Joined: Tue Sep 08, 2020 10:33 am

Re: 2017 Miata Grand Touring CEL

Post by JoeA217 »

Will have that secondary O2 sensor checked. The 1st O2 sensor is not pinched. Thanks Brian!
JoeA217
Posts: 6
Joined: Tue Sep 08, 2020 10:33 am

Re: 2017 Miata Grand Touring CEL

Post by JoeA217 »

Hey Brian,
I apologize for not getting back to you sooner. I had the lines check on my O2 sensors and neither one of them is pinched at a hard angle. I didn’t mention previously that the after market headers did not come with a cat converter like the one that’s on the OEM headers. Current state, there’s only one that came with the mid pipe.

Thanks,
Joe
Brian
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Re: 2017 Miata Grand Touring CEL

Post by Brian »

One of your codes is cat efficiency and with just 1 converter way back in the midpipe that can just happen on cold days since it takes so much longer to heat up and fire off back in the midpipe compared to where the sensors are normally located immediately before and after the header converter. That second code for lean concerns me more. Possible causes can be a leak somewhere in the system or something up front like a dirty injector, etc. It can be a challenge to understand if car actually running lean because of some issue up front like injector or vacuum leak.... or is car not running lean at all and the false code is because of some exhaust system leak or issue with the sensor as mounted or failing sensor? Start with getting car on the lift and running on the lift and go around looking for exhaust leak, also check under the hood with car running for vacuum leak. Check plugs too, deposits on each will tell you something about how each cylinder is running, clean and gap to stock specs again or replace any that look very different than the rest.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
JoeA217
Posts: 6
Joined: Tue Sep 08, 2020 10:33 am

Re: 2017 Miata Grand Touring CEL

Post by JoeA217 »

There are no exhaust leaks or any leaks under the hood. It’s been thoroughly checked. Plugs are only a couple of months old and no misfire. Sensors are good, as there were no codes prior to the upgrade. Basically, the car was running just fine after it was serviced and certified by the Mazda dealership.
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