Exhaust Install issue - stripped
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Intermediate
Joined: Jul 2013
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Exhaust Install issue - stripped
Installing a Corsa Exhaust.
Tried to remove the nut on the drivers side bolt between cat back and the catalytic converter. It seems to be a press fit bolt (15mm nut). I accessed the nut with a 24inch extension from the rear as instructed but it turned the press fitting instead of loosening the nut.
What are my options?? Got the car up on the lift still.
Tried to remove the nut on the drivers side bolt between cat back and the catalytic converter. It seems to be a press fit bolt (15mm nut). I accessed the nut with a 24inch extension from the rear as instructed but it turned the press fitting instead of loosening the nut.
What are my options?? Got the car up on the lift still.
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Intermediate
Joined: Jul 2013
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Well clearly I shouldn't have followed CORSA's directions because IT"S WELL WORTH IT to remove the intake cover in the trunk to access the bolts that way. Not even a question.
I removed the right side bolt on the cat and that exhaust flange is completely loose...but that left side nut isn't going anywhere and the bolt now spins freely in the cat. I will probably cut the bolt in half and knock the press fit bolt out the back of the cat. Then I'll just push a standard bolt through the back of the CAT.
I considered buying some high flow cat's but, not sure I would find somebody to pass me in CA. Wondering what they would do if CAT's had blankets on them.
I removed the right side bolt on the cat and that exhaust flange is completely loose...but that left side nut isn't going anywhere and the bolt now spins freely in the cat. I will probably cut the bolt in half and knock the press fit bolt out the back of the cat. Then I'll just push a standard bolt through the back of the CAT.
I considered buying some high flow cat's but, not sure I would find somebody to pass me in CA. Wondering what they would do if CAT's had blankets on them.
Race Director
Joined: Jan 2014
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From: Fulshear, TX
Not that I'm condoning intentionally violating your state's emissions requirements, but... EOS does offer a high-flow cat solution that reuses your stock cat heatshields which should do a pretty good job of getting around a visual inspection. The built-in o2 spacer to maintain sensor location with stock heatshields in place should also defeat any check engine light or associated error code.
Sorry CARB, I do apologize!
https://extremeonlinestore.com/produ...ytic-converter
Sorry CARB, I do apologize!
https://extremeonlinestore.com/produ...ytic-converter
Race Director
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From: Fulshear, TX
So, I did a bit more digging and as the appearance and price may suggest, these are actually cat-delete resonators, but they do look nearly stock with the heatshields in place and apparently do not trigger a CEL per a YouTuber who installed them:
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From: Fulshear, TX
Race Director
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From: Fulshear, TX
Thread Starter
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My dealership said changing the cats affects O2 readings and therefore fuel trim etc and therefore voids your engine warranty. Same thing for changing the intake box, throttle body etc....non-gm filter probably okay (but who cares). So I'm not going to be doing either of those things (for now). I guess I'll focus on the outside of the car instead.
As for an update on the original topic. I got the exhaust out and switched over to the CORSA. Sounds good.
I did need to move the car slightly AFTER I had started the disassembly process, so the valve connections were disconnected. This threw two codes and a CEL once I got everything back to together and finished. That code may have eventually cleared itself after 8-10 start cycles, but I went to GM and they cleared for free and it hasn't came back yet. Did not do a valve relearn, doesn't seem to be necessary yet. Valves working as expected.
As for an update on the original topic. I got the exhaust out and switched over to the CORSA. Sounds good.
I did need to move the car slightly AFTER I had started the disassembly process, so the valve connections were disconnected. This threw two codes and a CEL once I got everything back to together and finished. That code may have eventually cleared itself after 8-10 start cycles, but I went to GM and they cleared for free and it hasn't came back yet. Did not do a valve relearn, doesn't seem to be necessary yet. Valves working as expected.
Race Director
Joined: Jan 2014
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From: Fulshear, TX
My dealership said changing the cats affects O2 readings and therefore fuel trim etc and therefore voids your engine warranty. Same thing for changing the intake box, throttle body etc....non-gm filter probably okay (but who cares). So I'm not going to be doing either of those things (for now). I guess I'll focus on the outside of the car instead.
As for an update on the original topic. I got the exhaust out and switched over to the CORSA. Sounds good.
I did need to move the car slightly AFTER I had started the disassembly process, so the valve connections were disconnected. This threw two codes and a CEL once I got everything back to together and finished. That code may have eventually cleared itself after 8-10 start cycles, but I went to GM and they cleared for free and it hasn't came back yet. Did not do a valve relearn, doesn't seem to be necessary yet. Valves working as expected.
As for an update on the original topic. I got the exhaust out and switched over to the CORSA. Sounds good.
I did need to move the car slightly AFTER I had started the disassembly process, so the valve connections were disconnected. This threw two codes and a CEL once I got everything back to together and finished. That code may have eventually cleared itself after 8-10 start cycles, but I went to GM and they cleared for free and it hasn't came back yet. Did not do a valve relearn, doesn't seem to be necessary yet. Valves working as expected.
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Your dealer (service advisor?) is wrong. The o2 sensors that impact your fuel trims are in the headers upstream of the cats. I'd probably find a different dealership service department if I were you if you plan to mod your car. If he's taking such a hardline stance against all these stock tune compliant bolt-ons then I'd surely be suspect of what he'll think about your Corsa catback.
Kracka, I agree on changing dealers. They cleared my code at the dealer but didn't do the relearn. The code came back. I saw that you used the creader elite in another post to do the relearn, so rather than go back to that dealer I bought the scan tool. But I'm having problems with the "learn" procedure. I think I might need to adjust the rod length on the valve. Would appreciate you looking at that other thread and helping me out with how you did the learn. Mine just doesn't seem to do anything.
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Last edited by Andybump; Jul 3, 2023 at 09:51 AM.
Le Mans Master
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From: Sausalito CA
OP..LBC... perhaps an air wrench, super speed, will remove the nut?
Maybe heat the nut first?
A little spot welding on the press fit?
Not sure how to get tension on the press fit head.
Your idea to cut and replace seems valid.
Calif smog... includes a visual... so with a coupe you may fail, blankets or not.
Good luck.
Maybe heat the nut first?
A little spot welding on the press fit?
Not sure how to get tension on the press fit head.
Your idea to cut and replace seems valid.
Calif smog... includes a visual... so with a coupe you may fail, blankets or not.
Good luck.