$EE tuning questions

[Dirtybob]

Recently installed a wideband (along with headers/new exhaust) on my '95 Roadmaster and was noticing that the car 'hangs on' to enrichment for a short time even after lifting the throttle (I'm assuming this is normal behavior) and will also go rich (12:8/13.0:1 afr) with increased load on the interstate (i.e. fighting a headwind or climbing a hill) but it does not show as power enrichment on my logs. This is happening at less than 22% tps and below 50 kpa map.
Wondering if anyone has encountered this before and if it's worthwhile to try to tune it out (better highway mpg)?

Also had to remove the egr for the new headers and thought I had tuned it out but I still see blips of 15% egr duty cycle on my logs - is this anything to be concerned about? The system is physically incapable of doing anything, vac & electrical are unplugged and blocked off.

[johnny_b]

You can always unplug the EGR and disable the check engine light codes associated with it just to be sure.

The enrichment you’re seeing sounds like cat protect. Afr goes rich to protect the cats. Just disable it, shouldn’t be an issue

[Dirtybob]

You can always unplug the EGR and disable the check engine light codes associated with it just to be sure.

Already did the above. I also set the egr enable min map to 104 kpa, min rpm to 6375, and zeroed out the egr spark advance correction table. I see there are still quite a few egr related parameters that I left untouched (EEXTRA/Tunerpro)...


The enrichment you’re seeing sounds like cat protect. Afr goes rich to protect the cats. Just disable it, shouldn’t be an issue

I had the same thought after posting this yesterday, I'll disable it and report back, thanks.

[johnny_b]

Already did the above. I also set the egr enable min map to 104 kpa, min rpm to 6375, and zeroed out the egr spark advance correction table. I see there are still quite a few egr related parameters that I left untouched (EEXTRA/Tunerpro)...



I had the same thought after posting this yesterday, I'll disable it and report back, thanks.

Ok then your EGR is disabled, don’t worry about the 15%duty cycle your seeing as it’s physically impossible for it to activate if it’s not connect to the harness.

also you may look at zeroing the EGR spark table adder if there is one, in-case that 15% dc is fooling the pcm thinking that the EGR is still activating (even tho it physically can’t) and adding or retarding spark

[ony]

I would zero it it might change your pulse with?

[jthompson122183]

max out these two constants and the "blips of 15%" should go away

2617 EGR Enable - Coolant Temp(Hi Startup MAT)
2618 EGR Enable - Coolant Temp(Low Startup MAT)

[Dirtybob]

max out these two constants and the "blips of 15%" should go away

2617 EGR Enable - Coolant Temp(Hi Startup MAT)
2618 EGR Enable - Coolant Temp(Low Startup MAT)

This worked, not seeing any EGR activity in my logs now.

I maxed out the 1292F CAT Protect - Min Coolant Temp (set to 151 Deg C) and am still seeing the odd fuel enrichment activity.
Assuming that this fuel is coming from the CAT Protect routine I'm going to try maxing the CAT Protect Min Temp @ Low/Mid/High and see what happens.
Any suggestions welcome...

[Dirtybob]

Just had the bright idea to compare my bin to a '95 Caprice SS (export) bin.
In addition to the 1292F Min Coolant Temp being maxed; 12929, 1292B, 1292D (CAT Protect Min Temp Low/Mid/High) were also maxed out.
1292E CAT Time before use... is zeroed
12930 CAT Default Temp is maxed

Will try these settings no later than tomorrow after work and post back, however I think it will be fully disabled after this.

[jthompson122183]

This worked, not seeing any EGR activity in my logs now.
That was the same for me also.


Assuming that this fuel is coming from the CAT Protect routine I'm going to try maxing the CAT Protect Min Temp @ Low/Mid/High and see what happens.

That will keep the Cat Protect from kicking in then dumping fuel to cool the Cat. Answered your own question.

[Dirtybob]

I was initially under the (mistaken) impression that maxing the '1292F CAT Protect - Min Coolant Temp' was all that was needed to disable the system.
I've seen the same (incorrect) info elsewhere when searching so I posted it all here...
I will post back after verifying that this does the trick.

[Dirtybob]

Verified, no more CAT Protect routine.