GEN 5 CAT delete- Fuel Smell reduction at idle

[Terry Wood]

I have read until my eyes were about ready to jump out of my face. There is a lot of information for GEN 4 and below but it seems many menu items have changed with the GEN 5 DI motor.

Can anyone point me at a good source to reduce the fuel smell at idle? I have been all over the different tables and options for SOI and EOI in the fuel general tab and want to adjust the EOI Split Idle table but don't know which way to go and read that it will not help my cause.

This is on a 2015 5.3L Sierra with CAT delete. I have attached to tune file for all the items adjusted thus far:

COT disable and enrichment zero'd.
CAT Warm-up disabled (I think).
CAT test diabled.
All downstream codes disabled and SES unchecked.

[kevin87turbot]

You'd certainly be able to clean up the raw fuel smell by optimizing EOI on a modified engine...specifically one with a larger than stock cam. However, you'll be hard pressed to clean up the smell on a stock engine, other than the changes that you have already made to the CAT warm up and COT.

[RobZL1]

!Cats is gonna stink. That smell you have now will always be there. With a cam, it gets the raw fuel smell, which you can then clean up, but the !cats smell remains there, too. Go flex fuel. It'll fix that right up and make it smell nice.

[IARLLC]

"Split Factor Cat Lightoff" does about 40% of injection during a second pulse whenever cat lightoff is active (so that raw fuel will go into the cat). I adjust it down to 0. I also sometimes just disable split pulse completely. With a louder exhaust you can get a pretty good bang during cranking if you don't disable it.

Not sure exactly what would be right, but for SOI Cat Lightoff I make the table more similar to base SOI. EOI Split Cat Lightoff, I also make more similar to EOI Split base (150).

Of course there is more fuel smell than a catted rig but these changes made a positive difference on catless L86 race trucks.

I went ahead and made the suggested changes to your file but the uploader is acting strangely. I'll upload it pretty soon and you can compare it with yours to see what you think.

I finally got the file to upload. Must be the browser on my other tuning laptop. Please let me know if this helps your fuel smell.

[Terry Wood]

"Split Factor Cat Lightoff" does about 40% of injection during a second pulse whenever cat lightoff is active (so that raw fuel will go into the cat). I adjust it down to 0. I also sometimes just disable split pulse completely. With a louder exhaust you can get a pretty good bang during cranking if you don't disable it.

Not sure exactly what would be right, but for SOI Cat Lightoff I make the table more similar to base SOI. EOI Split Cat Lightoff, I also make more similar to EOI Split base (150).

Of course there is more fuel smell than a catted rig but these changes made a positive difference on catless L86 race trucks.

I went ahead and made the suggested changes to your file but the uploader is acting strangely. I'll upload it pretty soon and you can compare it with yours to see what you think.

I finally got the file to upload. Must be the browser on my other tuning laptop. Please let me know if this helps your fuel smell.

Thank you for the file. I made some adjustments to your adjustments for any RPM above 1000/1200. Under mild driving, the truck seemed to "fall on its face" during shifts when RPM dropped below 1500. I may make even more adjustments closer to stock for RPMs above 1000 or at the 1200 mark.

I need to learn more about how adjusting injector settings affects operations. I may just get the truck tuned by someone that does this for a living, who would you recommend?

12- 5SEP2020- Speed, DOD, COT disable, Min Enrich to zero, Cat Warm-up disabled, Cat Test disabl.hpt

[IARLLC]

Several of the guys on here can do a great job on GEN5 stuff but I would recommend GHuggins above all.