[cb2188]

Hey guys, I wanted to know your opinions on catted vs catless DP's since I am considering buying DP's for my 335xi. I prefer to go with catted since it prevents the engine light from coming on which would also avoid any questions when I bring my car in to get serviced. Is there a difference in performance? And is there any DP recommended for S1 Dinan?

[parky1215]

Most downpipe with high flow cat will also throw engine light. On my previous car (135i), I had icarbon downpipe with 300 cell metal cat. It threw SES light after few hundred miles of driving.

[benzy89]

You'll get a SES/CEL unless you change your tune (COBB, GIAC, JB4, PROcede) for any aftermarket DPs -- High flow cats or Catless


The OEM/Dinan DME is going to sense the increased emissions & trigger the code thinking that something's wrong.


Change tunes & scrap the cats completely

[bigdaddycane]

Originally Posted by benzy89

Change tunes & scrap the cats completely

^ This

[335ikiid]

you could always just get a bms dp fix

[benzy89]

^^^That'll interfere with the AFRs & could cause the car to unintentionally run rich/too lean

It's recommended that once you use the BMS DP Fix to pass an inspection test, that you remove it again before ripping on the car

[cb2188]

Thanks for the advice! Even if I do get a check engine light I'm sure there is a code that could eliminate it no?

[benzy89]

One of the mainstream tunes (COBB, JB4 or PROcede) will automatically cancel out a CEL triggered by going catless. It'll allow other non-tuner related codes to pop up if something else needs to be serviced


Before buying another tune though, I'd recommend you find out if you need to unflash the Dinan tune before running something on top of it

[ihc95]

Originally Posted by benzy89

One of the mainstream tunes (COBB, JB4 or PROcede) will automatically cancel out a CEL triggered by going catless. It'll allow other non-tuner related codes to pop up if something else needs to be serviced


Before buying another tune though, I'd recommend you find out if you need to unflash the Dinan tune before running something on top of it

Hey look who's back! Lol

[cb2188]

Originally Posted by benzy89

One of the mainstream tunes (COBB, JB4 or PROcede) will automatically cancel out a CEL triggered by going catless. It'll allow other non-tuner related codes to pop up if something else needs to be serviced


Before buying another tune though, I'd recommend you find out if you need to unflash the Dinan tune before running something on top of it

I wouldn't want to get rid of the Dinan tune since i've already spent a lot of money of it and I like the fact that the power is always there when I want it!

[ragingpanda]

Originally Posted by cb2188

I wouldn't want to get rid of the Dinan tune since i've already spent a lot of money of it and I like the fact that the power is always there when I want it!

Dinan and power don't really belong in the same sentence.

[bigdaddycane]

Originally Posted by ragingpanda

Dinan and power don't really belong in the same sentence.

and true

cb2188, I know you paid a lot of money, but listen to the masses....the Dinan tune is NO where near the JB4, COBB or Procede tunes. Night and day....

[benzy89]

Originally Posted by ihc95

Hey look who's back! Lol

Haha see how long it lasts this time around

Originally Posted by cb2188

I wouldn't want to get rid of the Dinan tune since i've already spent a lot of money of it and I like the fact that the power is always there when I want it!

Since it's Dinan, you def spent a lot of money, and at the end of the day, all that matters is that you're happy with what you got. BUT since you inquired about catless DPs, Dinan prob won't be able to do anything about that.

[King mode]

Keep in mind, there are only catless dp's avail for xi...

[cb2188]

Originally Posted by King mode

Keep in mind, there are only catless dp's avail for xi...

Good to know. Thanks.

[cb2188]

Originally Posted by benzy89

Haha see how long it lasts this time around



Since it's Dinan, you def spent a lot of money, and at the end of the day, all that matters is that you're happy with what you got. BUT since you inquired about catless DPs, Dinan prob won't be able to do anything about that.

I am very happy with the performance but like most people, I am always trying to find an upgrade to get extra HP without putting a hole in my wallet. Considering it is my first BMW I should have done more investigation on the tuning options but I like Dinan because of the warranty which provides a peace of mind. I know Dinan doesn't make DP's but my concern about getting DP's is a possible problem concerning my warranty.

[zztwinturbozz]

Originally Posted by cb2188

I am very happy with the performance but like most people, I am always trying to find an upgrade to get extra HP without putting a hole in my wallet. Considering it is my first BMW I should have done more investigation on the tuning options but I like Dinan because of the warranty which provides a peace of mind. I know Dinan doesn't make DP's but my concern about getting DP's is a possible problem concerning my warranty.

You do realize that Dinan only runs concurrent with the factory 4 year 50k mile warranty right? You have an 09? Won't be covered soon anyway.

[Chrisred]

Originally Posted by benzy89

^^^That'll interfere with the AFRs & could cause the car to unintentionally run rich/too lean

It's recommended that once you use the BMS DP Fix to pass an inspection test, that you remove it again before ripping on the car

Is there a way to reset the AFR's once u remove DP fix to get things back to "normal"??

[cb2188]

Going back to my original question is there any difference in HP gains between the catted or catless DP's?

[benzy89]

Originally Posted by cb2188

Going back to my original question is there any difference in HP gains between the catted or catless DP's?

~20 WHP from OEM to Catless

[Sered]

Originally Posted by benzy89

^^^That'll interfere with the AFRs & could cause the car to unintentionally run rich/too lean

Once again, you're providing misinformation. The DPFix works on the post cat sensors; those sensors are not used for monitoring or determining AFR. Those sensors are used for NO emissions compliance by determining that there is an ample difference between the main O2 sensors and the post-cat O2 sensors.

[MDORPHN]

Originally Posted by Sered

Once again, you're providing misinformation. The DPFix works on the post cat sensors; those sensors are not used for monitoring or determining AFR. Those sensors are used for NO emissions compliance by determining that there is an ample difference between the main O2 sensors and the post-cat O2 sensors.

Not quite accurate. They detect degradation of the cats and, as the cats are become less effective, do affect fuel trim.

Neil