Tune ONLY for cat delete?

[BMW135pls]

My JB4 equipped 135i is in the shop for its dp install, but the JB4 is not equipped to handle a cat delete. At this point I'm not really sure I want to layer the JB4 with another performance tune as I'm more or less happy with what the car is doing. I may be wrong but I when I think of layering the tunes, I think of lowered gas mileage and increased engine wear (The JB4 waits until the engine is fully warm before the tune kicks in, where a chiptune will not). Plus I've been getting between 18.5-20mpg even with the JB4 engaged, and I'm pretty happy with that. I've already emailed Cobb and asked if they were willing to write a tune that was JUST a cat delete and not a performance tune, but they never responded. I'm about to email more tune shops, but I'm afraid I will get the same response.

[mike@x-ph.com]

Not sure what you mean by the Jb4 is not equipped to handle cat delete

[BMW135pls]

Originally Posted by mike@x-ph.com

Not sure what you mean by the Jb4 is not equipped to handle cat delete

I remember reading that due to backlash some years ago, BMS decided to now only hide the CEL light as opposed to deleting the actual codes from a dp install, so they're still there.

[mike@x-ph.com]

Originally Posted by BMW135pls

I remember reading that due to backlash some years ago, BMS decided to now only hide the CEL light as opposed to deleting the actual codes from a dp install, so they're still there.

I cannot confirm or deny that but if the codes are hidden why is bothering you?

[BMW135pls]

Originally Posted by mike@x-ph.com

I cannot confirm or deny that but if the codes are hidden why is bothering you?

Cause I think the codes will still cause you to fail the new style emissions tests even if they don't cause a CEL.

[mike@x-ph.com]

Originally Posted by BMW135pls

Cause I think the codes will still cause you to fail the new style emissions tests even if they don't cause a CEL.

Even if code is deleted you will still fail emission.

[uberbeast21]

Thats why you can buy a dp fix...

[BMW135pls]

Originally Posted by uberbeast21

Thats why you can buy a dp fix...

I have an X-Kitty dp fix, but I don't know how to install it, and I've heard it can cause damage if you leave it on for too long. What do you do, turn it on when you go for emissions and turn it off after that?

[uberbeast21]

Originally Posted by BMW135pls

I have an X-Kitty dp fix, but I don't know how to install it, and I've heard it can cause damage if you leave it on for too long. What do you do, turn it on when you go for emissions and turn it off after that?

I dont know from experience but once installed you need to put the car through a drive cycle to get readiness and adjust the dp fix as necessary

[darkrom]

Originally Posted by BMW135pls

I have an X-Kitty dp fix, but I don't know how to install it, and I've heard it can cause damage if you leave it on for too long. What do you do, turn it on when you go for emissions and turn it off after that?

When it is emissions time install your DP fix. Disable JB4 by setting it to map 0. Drive 100 miles or so and go get your inspection. I think you can have autozone "check readiness" before you gamble on an inspection.


BTW cobb does the same thing. Disables the code from displaying. You will still fail emissions with cobb + a downpipe the exact same way you will with JB4. Both devices make the code not annoy you, but that is it.