If I get testpipes without a tune will it mess up anything?

[SflBimmer8484]

Originally Posted by Koldun

I actually enjoyed doing all my performance mods one at a time to see if the butt dyno detects anything.

That's understandable.

[Patrón]

Originally Posted by Gfunk720

The CEL is for catalyst deficiency. It does not put the car into limp mode.

I agree that the catalyst deficiency is what would trigger it , but if something else were to trigger it, wouldn't "limp mode" usually come on whenever the CEL comes on?

Actually waiting for Mr. Benvo to chime in. he knows his shit.

[Hujan]

Originally Posted by chris3g

does anyone know if this will cause a CEL?

I don't believe so.

[BPMSport]

Originally Posted by Patrn

I agree that the catalyst deficiency is what would trigger it , but if something else were to trigger it, wouldn't "limp mode" usually come on whenever the CEL comes on?

Actually waiting for Mr. Benvo to chime in. he knows his shit.

In these cars the CEL or check engine light is called the SES or service engine soon light (for NA spec vehicles).

It can illuminate for cat efficiency, or a number of other issues. If not a serious issue, only the SES will illuminate in the cluster. This indicates that there are one or more emissions related faults.

Limp mode means that you'll also have engine malfunction warnings on the iDrive, as well as an outline of an engine half shaded in the center of the instrument cluster display.

You can have an SES without limp mode, but you can not have limp mode without having an SES light.

The issue with having the light on is that you will not know of other issues that would illuminate the SES light. If a more serious condition occurs, then you'll get limp mode accompanied with the half shaded engine in the cluster. The image for the SES in the center display is only an outline, and is not shaded at all. You'll see this upon starting and it will go away if there is an emissions fault. The limp mode warning with the half shaded engine will not clear from the center of the cluster.

It is definitely suggested and recommended to get a proper tune when going with a Catless setup. The reason is that the decreased back pressure calls for changes to camshaft timing which will optimize engine operation when the restrictive factory catalysts aren't present. The second benefit, of course, is suppressing the SES light and increased emissions earnings.

Hope this helps

[Patrón]

Originally Posted by Mike Benvo

In these cars the CEL or check engine light is called the SES or service engine soon light (for NA spec vehicles.

It can illuminate for cat efficiency, or a number of other issues. If not a serious issue, only the SES will illuminate in the cluster. This indicates that there are one or more emissions related faults.

Limp mode means that you'll also have engine malfunction warnings on the iDrive, as well as an outline of an engine half shaded in the center of the instrument cluster display.

You can have an SES without limp mode, but you can not have limp mode without having an SES light.

The issue with having the light on is that you will not know of other issues that would illuminate the SES light. If a more serious condition occurs, then you'll get limp mode accompanied with the half shaded engine in the cluster. The image for the SES in the center display is only an outline, and is not shaded at all. You'll see this upon starting and it will go away if there is an emissions fault. The limp mode warning with the half shaded engine will not clear from the center of the cluster.

It is definitely suggested and recommended to get a proper tune when going with a Catless setup. The reason is that the decreased back pressure calls for changes to camshaft timing which will optimize engine operation when the restrictive factory catalyst a aren't present. The second benefit, of course, is suppressing the SES light and increased emissions earnings.

Hope this helps

Thank you for the post.

[M3-S65]

I don't know why someone would not just get the tune and get rid of the code....
However, I used to own a 2005 Dodge SRT4 and we would simply install a defouler in the exhaust and essentially "trick" the ECU into thinking the the cat was still there. Is this an option or are these cars to high tech to trick...Lol

Here is an example:
http://www.modernperformance.com/pro...harged_exhaust

[chris3g]

Originally Posted by M3-S65

I don't know why someone would not just get the tune and get rid of the code....
However, I used to own a 2005 Dodge SRT4 and we would simply install a defouler in the exhaust and essentially "trick" the ECU into thinking the the cat was still there. Is this an option or are these cars to high tech to trick...Lol

Here is an example:
http://www.modernperformance.com/pro...harged_exhaust

well a tune is $1000 and if you didn't care about the small amount of extra power it will get you, you could just clear the code in 5 seconds when it comes up every few hundred miles with your phone and a $20 OBD>BT adapter.