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Dp and exhaust install now have a stutter in idle

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Fort Worth, TX, USA
#1
after I had installed both items plugged everything back up I began to have this wierd idle.

now I had been waiting for the downpjpe for 3-4 weeks pretty much a month but I had another car so every know and then I would just run her with no pipes but the oem down pipe so she wasn’t just sitting there but I’m just a little confused and some extra tips would be greatly appreciated 👍🏼
 


haste

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#3
You have the oxygen sensors installed in the correct positions?
 


OP
I
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Thread Starter #7
Does you new DP have a Cat? If it doesn't that second O2 sensor is going to ball everything up.
I mean I purchased a catted one but it wouldn’t hurt to remove it and try right ? The second hole was plugged when I received it how would I be able to tell if it’s catted or not ?
 


Erick_V

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#8
The car will run fine even with the rear 02 unplugged/turned off. The sensor is only there to ensure the cat is working as it should, hence the P0420 cat efficiency code people get after going catless. The rear O2 doesn’t have an effect on the tune at all. You could try reflashing your tune and having it relearn. Would be a good idea to go over the intake also as you had to remove it to gain access to the DP
 


OP
I
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Thread Starter #9
The car will run fine even with the rear 02 unplugged/turned off. The sensor is only there to ensure the cat is working as it should, hence the P0420 cat efficiency code people get after going catless. The rear O2 doesn’t have an effect on the tune at all. You could try reflashing your tune and having it relearn. Would be a good idea to go over the intake also as you had to remove it to gain access to the DP
So I haven’t tuned the car yet you think that could be causing the stutter too ?
 


Erick_V

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#11
Even with my 3" Catted DP I would occasionally get the P0420, I installed a 90 degree Vibrant Defouler and that has since solved the issue.
 


OP
I
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Thread Starter #12
Even with my 3" Catted DP I would occasionally get the P0420, I installed a 90 degree Vibrant Defouler and that has since solved the issue.
So I started the car this morning before work checked the codes again and it’s saying below threshold efficiency bank 1 any recommendations on things I should check ?
 


Ford ST

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#13
What aftermarket downpipe do you have?

Aftermarket downpipes can absolutely throw that code they do not do their job nearly as well as the OEM part.

Sent from my LG-LS997 using Tapatalk
 


Last edited:
OP
I
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Fort Worth, TX, USA
Thread Starter #14
What aftermarket downpipe do you have?

Aftermarket downpipes can absolutely throw that coat they do not do their job nearly as well as the OEM part.

Sent from my LG-LS997 using Tapatalk
Whoosh catted down pipe is the one I ordered
 


Ford ST

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#17
You can use a defouler. I believe a proper tune would also solve this problem.


Sent from my LG-LS997 using Tapatalk
 


Erick_V

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#19
I appreciate all the information!! Any recommendations on possible tuning company’s ?
I’m currently running a Dizzy tune. You can get a flash tune for pretty cheap and it’ll feel great. If you get an intercooler you’ll be able to make like 80% of the power possible on the stock turbo. If you have access to E85 get an E30 tune and you’ll be glad you did.
 


OP
I
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Thread Starter #20
I’m currently running a Dizzy tune. You can get a flash tune for pretty cheap and it’ll feel great. If you get an intercooler you’ll be able to make like 80% of the power possible on the stock turbo. If you have access to E85 get an E30 tune and you’ll be glad you did.
Y’all think it’s okay to drive it without the tune and for how long ?
 


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