Greddy Supreme SP causing CEL?

[AlexBRZ2]

Hi everyone,

I was looking into getting a cat back exhaust soon and really like the Greddy Supreme SP catback. I want a rumble but not something crazy loud and not too much drone. The only mod I have so far is a UEL ftspeedfactory header.

My concern/question: I found a YouTube video (link:

) and they have the same header as me as well as the catback system I want. Only difference is that they have a Motiv catted front pipe, which I plan to keep stock. They said they got a CEL about 7k miles after install and was able to remove it with an OFT. I don’t believe I would have a check engine light but I am hoping to not have to get an OFT at this time if I wanted this exhaust. Does anyone have any kind of insight in if I would have to expect a CEL if I got thuan exhaust? I was thinking as long as I kept cats on, I wouldn’t have to really worry about a CEL with what I am doing.

Thanks in advance!

[Clipdat]

"The only mod I have so far is a UEL ftspeedfactory header." is it catted?

[Lightened]

No - aftermarket exhausts alone do not cause the Check Engine Light (CEL) to turn on.

An aftermarket header without a Catalytic Converter may cause the CEL to come on.

[Gamace]

Originally Posted by AlexBRZ2

Hi everyone,



I was looking into getting a cat back exhaust soon and really like the Greddy Supreme SP catback. I want a rumble but not something crazy loud and not too much drone. The only mod I have so far is a UEL ftspeedfactory header.



My concern/question: I found a YouTube video (link:

) and they have the same header as me as well as the catback system I want. Only difference is that they have a Motiv catted front pipe, which I plan to keep stock. They said they got a CEL about 7k miles after install and was able to remove it with an OFT. I don’t believe I would have a check engine light but I am hoping to not have to get an OFT at this time if I wanted this exhaust. Does anyone have any kind of insight in if I would have to expect a CEL if I got thuan exhaust? I was thinking as long as I kept cats on, I wouldn’t have to really worry about a CEL with what I am doing.



Thanks in advance!

Did you tune your car after installing the headers?

Toyota 86 in the building!

[AlexBRZ2]

Originally Posted by Clipdat

"The only mod I have so far is a UEL ftspeedfactory header." is it catted?

Realized a couple more details I may have left out, sorry. My header isn’t catted and I did not tune it after. I know ftspeedfactory said that no tune was needed. I am kind of hoping to avoid tuning my car until the factory warranty lapses in the instance something wild happens to my engine and the warranty will cover it and the dealership won’t try to blame it on the tune. That’s the main reason why I am hoping a tune isn’t necessary for the Greddy Supreme SP catback.

I am planning on keeping cats on my exhaust as well.

[DarkPira7e]

By "no tune needed" they meant it won't explode, but it is unequivocally the cause of your check engine light

[AlexBRZ2]

Originally Posted by DarkPira7e

By "no tune needed" they meant it won't explode, but it is unequivocally the cause of your check engine light

I don’t have check engine light. My car is running perfectly. I just want to make sure I won’t need to tune my care if I decide to add the catback exhaust.

The check engine light that I brought up was because someone who posted a YouTube video had a CEL with the same header, catback that I want, but a Motiv catted front pipe. I plan to keep the stock front pipe.

[DarkPira7e]

Originally Posted by AlexBRZ2

I don’t have check engine light. My car is running perfectly. I just want to make sure I won’t need to tune my care if I decide to add the catback exhaust.

The check engine light that I brought up was because someone who posted a YouTube video had a CEL with the same header, catback that I want, but a Motiv catted front pipe. I plan to keep the stock front pipe.

Sorry, I misunderstood! No, the catback won't change a thing

[AlexBRZ2]

Originally Posted by DarkPira7e

Sorry, I misunderstood! No, the catback won't change a thing

No worries, thank you!

[Joveen]

Seems you just got into the modding game. A catback cannot and will not cause CEL. The header without a tune for sure will. Not sure why you would get an aftermarket header and not tune the car. With the oft you can always flash back to stock on the fly. Just a tune and forget the warranty that you might not even use.

Sent from my SM-N960U using Tapatalk

[AlexBRZ2]

Originally Posted by Joveen

Seems you just got into the modding game. A catback cannot and will not cause CEL. The header without a tune for sure will. Not sure why you would get an aftermarket header and not tune the car. With the oft you can always flash back to stock on the fly. Just a tune and forget the warranty that you might not even use.

Sent from my SM-N960U using Tapatalk

Yeah, I’m definitely new to the modding game. I just cannot come to tune the car, void the warranty, and then think to myself if something wrong happens, have the thought that the dealer won’t help fix the issue by blaming it on the tune.

If the car has been running fine without a tune, would the tune only be necessary in order to increase the performance gains or would it potentially prevent something from happening that would have been a result of the header? Also, if I flash it back to stock, won’t the dealer see a change?

[alphasaur]

Originally Posted by AlexBRZ2

Yeah, I’m definitely new to the modding game. I just cannot come to tune the car, void the warranty, and then think to myself if something wrong happens, have the thought that the dealer won’t help fix the issue by blaming it on the tune.

If the car has been running fine without a tune, would the tune only be necessary in order to increase the performance gains or would it potentially prevent something from happening that would have been a result of the header? Also, if I flash it back to stock, won’t the dealer see a change?

I mean if they dealership really wanted to be ****heads and something happens to your engine they can likely tell that you swapped the header. Swapping the header can effect your AFR which can cause things to break. Is the likelihood high? No.

[Joveen]

Why buy the header and not get the most out of it?

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[AlexBRZ2]

Originally Posted by Joveen

Why buy the header and not get the most out of it?

Sent from my SM-N960U using Tapatalk

My thought process was to get a bit of a gain now and then when the warranty is gone, tune it to get the remainder of the reliable potential out of it.