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Discussion Starter #1
I have somewhat of a newbie question, is there any way that an exhaust install down-stream of the cat would cause it to go bad?


I'm battling a CEL after my install of the GWR full system and I have gone through a progression of codes, first that the O2 sensor was reading lean, then that it was getting a low voltage, and now that the cat is below the threshold of efficiency. Sometimes the codes clear on their own and sometimes I have to do it manually, which leads me to believe it's just something to do with the O2 sensor/wiring being damaged during the swap over. I'm trying to get it diagnosed professionally but no dealer in the Houston area will touch the car after the techs see the exhaust, even when I tell them about it when making the appointment, and they just clear the code and charge me their full rate for troubleshooting. So now I'm looking for a performance shop to take it to or something where they won't be terrified of a little larger pipe.


Jonathan
 

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I would expect you'd need to be actually running fairly rich for sometime to actually damage the cat. Are you experiencing any power loss or symptoms you'd associate with cat damage? I initially saw a lean reading after the GWR exhaust install while it seemed to be running rich, but have not seen a CEL in over 4 hundred miles now. It may help others advise if they know the exact codes and the number of miles between them.

I'm wondering if you tuned before or after the exhaust install. If you tuned first, did you do a hard reset of the ECU (disconnect the battery) after the exhaust install? Have you considered reverting to stock tune to eliminate the tune as a variable?

Sorry to hear your area dealers are not helpful, charge you but don't seem willing to install a new sensor at your cost? Anyway, with the info at hand, it seems like going to an independent to change out the sensor or troubleshoot is a logical next step before tearing into the cat (especially if you are not seeing actual evidence of cat damage.
 

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Some members of the German 124-spider forum had catalyzer and sensor issues after some tausend km even with the OE exhaust. FCA replaced the complete catalytic converter to fix that issue.
Maybe the full GWR exhaust causes your problem but maybe it is a generell problem with the FCA exhaust.
 

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Discussion Starter #4
I would expect you'd need to be actually running fairly rich for sometime to actually damage the cat. Are you experiencing any power loss or symptoms you'd associate with cat damage? I initially saw a lean reading after the GWR exhaust install while it seemed to be running rich, but have not seen a CEL in over 4 hundred miles now. It may help others advise if they know the exact codes and the number of miles between them.

I'm wondering if you tuned before or after the exhaust install. If you tuned first, did you do a hard reset of the ECU (disconnect the battery) after the exhaust install? Have you considered reverting to stock tune to eliminate the tune as a variable?

Sorry to hear your area dealers are not helpful, charge you but don't seem willing to install a new sensor at your cost? Anyway, with the info at hand, it seems like going to an independent to change out the sensor or troubleshoot is a logical next step before tearing into the cat (especially if you are not seeing actual evidence of cat damage.
I don't really have specific miles between codes, and to be honest I am new to having a sports car/manual car in general so I don't know what the symptoms of a bad cat would be other than the odor or overheating. I have put a total of around 2k miles since the install, here are the codes:


P2096: Post catalyst fuel trim system too lean bank 1
P0402: Catalyst system efficiency below threshold bank 1
P0137: 02 sensor circuit low voltage bank 1 sensor 2


I don't have a tune yet, but I have reset the ECU since the exhaust install. Right now I am waiting to get this issue resolved before I get the V4 intake and then get a tune once that is all installed.


And yea I really can't understand why the dealer won't do it when I've said I am willing to pay whatever cost to get it looked at and whatever it costs in parts to get it fixed. I may put the factory exhaust back on and see what happens if I can't find a local shop that will look at it.
 

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I have somewhat of a newbie question, is there any way that an exhaust install down-stream of the cat would cause it to go bad?


I'm battling a CEL after my install of the GWR full system and I have gone through a progression of codes, first that the O2 sensor was reading lean, then that it was getting a low voltage, and now that the cat is below the threshold of efficiency. Sometimes the codes clear on their own and sometimes I have to do it manually, which leads me to believe it's just something to do with the O2 sensor/wiring being damaged during the swap over. I'm trying to get it diagnosed professionally but no dealer in the Houston area will touch the car after the techs see the exhaust, even when I tell them about it when making the appointment, and they just clear the code and charge me their full rate for troubleshooting. So now I'm looking for a performance shop to take it to or something where they won't be terrified of a little larger pipe.


Jonathan
Hey Johnathan,

It sounds like this is an issue with the sensor itself or the wiring going to the sensor. It is likely not the CAT going bad, but the DTC codes the ECU is showing would make that determination much easier.

If you're in the Houston area, contact Bryan at NGEN Customs & Performance. He works almost exclusively on the 1.4L Multiair, and has quite a bit of experience with these cars. He also deals with us often, so we can help technically in anyway needed as well. I would give him a call and see if he can take a look at the exhaust system and sensor/wiring.
 

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I'm having this exact same issue with those exact same codes. They show up every 1,000 miles or so, then I clear them. I have the full Good-win Roadstersport exhaust (non-resonated). I always assumed I had a small leak at the crosspipe flange right before the rear o2 sensor. I decided to just deal with the codes until a catless downpipe comes out and I can turn off the rear o2 sensor with a tune. I believe Eurocompulsion said they are able to do that.
 

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I now have over 5000 miles on my GWR full Abarth system and have never had a Check Engine light.
Did the install myself but was extremely careful (obsessive actually) with the O2 sensor, and wiring, and ensuring no leaks upstream of the sensor.
I agree with the others that a bad CAT at this stage is extremely unlikely without a bad tune ( you have stock) or bad gas (poor driveability). Those codes are really only indicating that the output from the O2 sensor is not what the ECU is expecting.

Hopefully someone local will be willing to look a little deeper into this for you.

Best of luck and please keep us posted.
 

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Thanks for posting the codes. Those are most certainly exhaust related. It is either the sensor/sensor wiring damaged, or an exhaust leak.

I have seen them many times on the 500 Abarth platform, and it is almost always an exhaust leak. So anyone who gets these codes after replacing the exhaust, check the system for leaks, loose clamps, brackets or bolts, etc.
 

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I'm having this exact same issue with those exact same codes. They show up every 1,000 miles or so, then I clear them. I have the full Good-win Roadstersport exhaust (non-resonated). I always assumed I had a small leak at the crosspipe flange right before the rear o2 sensor. I decided to just deal with the codes until a catless downpipe comes out and I can turn off the rear o2 sensor with a tune. I believe Eurocompulsion said they are able to do that.
We can currently disable/optimize any CELs for running a high flow cat and/or catless, so yes we can do that. It will be available with Phase 2, among many other features we are working on.

However, we do not completely disable the sensor, it is optimized to function with a catless setup without throwing CELs, and still being enabled allows for proper emissions processing with the ECU (even though it takes a very long time to establish readiness with the CAT missing). So, these codes above are unrelated to what is thrown for a catless setup. Meaning that even with a catless downpipe and CEL elimination you will still get the above codes if it is in fact an exhaust leak. I would check it out if you suspect there's a leak and are getting these DTCs.
 

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Discussion Starter #10
Hey Johnathan,

It sounds like this is an issue with the sensor itself or the wiring going to the sensor. It is likely not the CAT going bad, but the DTC codes the ECU is showing would make that determination much easier.

If you're in the Houston area, contact Bryan at NGEN Customs & Performance. He works almost exclusively on the 1.4L Multiair, and has quite a bit of experience with these cars. He also deals with us often, so we can help technically in anyway needed as well. I would give him a call and see if he can take a look at the exhaust system and sensor/wiring.
So I did contact Bryan before I went back to the shop I installed it at, I installed it with my father and his friend at the shop they have behind their construction office. He said what has been stated here about a leak or bad wiring, but that he usually doesn't do troubleshooting things and focuses more on installs. We put it up and everything seems tight, I might contact Goodwin Racing about getting a new gasket to try at the joint of the downpipe and the crosspipe. There is no visible damage to the O2 sensor and we were very careful with it during the install, but I understand that doesn't mean the wire isn't damaged under the insulation. The only difference I've noticed is when the light is on the car backfires quite a bit on upshifts or when I take my foot of the gas while cruising in 6th, and I feel like it's a little harder for the car to get going.


Thanks for all the input!
 

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This issue is being reported with the full GWR exhaust quite a bit. I wonder if it's a build issue with the crosspipe or the full exhaust that is causing sealing issues of the crosspipe at the cat. I cannot believe every single person having this issue with this is exhaust has a wiring issue, or a bad sensor, or a bad cat.
 

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Every, every time I rebuild an exhaust...

Thanks for posting the codes. Those are most certainly exhaust related. It is either the sensor/sensor wiring damaged, or an exhaust leak.

I have seen them many times on the 500 Abarth platform, and it is almost always an exhaust leak. So anyone who gets these codes after replacing the exhaust, check the system for leaks, loose clamps, brackets or bolts, etc.
I use this stuff. Great piece of mind. It works.

https://www.eurosportacc.com/products/890100045?utm_medium=cpc&utm_source=googlepla&variant=241818125&gclid=Cj0KEQjwyN7JBRCZn7LKgb3ki8kBEiQAaLEsqsJxs9-Ig60HZnA8ffr8FLoWW4ryH24CfYGEMfQM3AQaAmdJ8P8HAQ

:)
 

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When my exhaust is in its final form (catless downpipe and resonated midpipe), I will be sure to use RTV on every flange. I don't plan on ever taking the exhaust off after that, so hopefully that will take exhaust leaks out of the equation.
 

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