CSL breather tube

[WBVenom]

Hmm, I ran with the original air rail,11157834056 CCV hose and my MSS54HP flashed with CSL Bootloader 32500 without issues for a few months prior to getting the Mullet Tune on my 2004 Vert. I have since switched to the CSL CCV hose and plugged the air rail with a vacuum cap.

Interesting. I too am running MSS54HP with CSL Bootloader 32500, with and without Mullet Tune. With the 11157834056 late-model breather hose connected to the 13417834068 late-model air rail, without fail I have a surging, rough idle during open-loop operation shortly after both cold and warm start, sometimes misfires, and sometimes EML and related codes. The instant I simply disconnect the breather hose from the air rail and plug the air rail as shown below, all issues resolve. Rock steady idle. No surging, smooth as butter, no misfires, no codes. Night and day.



Perhaps your breather valve somehow ends up in a closed/different state when the DME is ignoring it than mine does...

[Ramage]

WBVenom Yeah, it is odd that it was causing you issues. One thing I was thinking was maybe you have catalytic converters as well as have the SAP enabled. I am running without cats and have my SAP pump fully removed and hole blocked off.

I like the plug you used for your air rail, I capped mine off with one of these.

and while I was waiting from my dealership to bring in the 11157833649 (CSL Crank Case Vent Hose) I ordered I picked up a REIN Standard length breather hose from RockAuto and stretched it using a heat gun.
I figured for the $13 CDN it was worth trying, and I liked the idea of not having to cut the original hose with the adaptor for the valve.

[WBVenom]

Ramage


I do indeed have cats and have the SAP present and the SAP sequence enabled. Are you thinking the pressure from the SAP during SAP operation is pressurizing the crankcase (valvetrain area), the air from which then flows out of the CCV port, through the breather valve, and into the air rail? If so, this could absolutely explain my rough idle, which would occur only during SAP operation.

I had previously theorized that the rough idle stopped when the DME switched from open-loop operation to closed-loop operation once the O2 sensors were ready. But the rough idle ceasing could instead be correlated with the SAP pump turning off. Both the start of closed-loop operation and the SAP turning off likely happen around the same time.

The SAP turning off is an easily-discernible event. I will test by feeling for SAP vibration and observing the idle just before and after it turns off. And I will feel for airflow from the CCV port during SAP operation as well.

For your reference, I utilized this plug to plug the air rail nipple.

Out of curiosity, how did your heat stretching of the standard-length breather hose go? That seems like a solid alternative to the OE CSL plastic hose.

[Ramage]

Ramage


I do indeed have cats and have the SAP present and the SAP sequence enabled. Are you thinking the pressure from the SAP during SAP operation is pressurizing the crankcase (valvetrain area), the air from which then flows out of the CCV port, through the breather valve, and into the air rail? If so, this could absolutely explain my rough idle, which would occur only during SAP operation.

That or something in the Cat heating sequence, unfortunately that does not explain why it would be an issue on warm start or why it would be causing an EML light. You might be right that the valve is bad and never closes, I am not sure there is anything in the code that monitors that valve.

Out of curiosity, how did your heat stretching of the standard-length breather hose go? That seems like a solid alternative to the OE CSL plastic hose.

It was pretty straightforward I just went slow on the heat and took my time to get the length needed. If I did not already have the OG CSL hose already on the way I would have just kept using the stretched one.