Commanded AFR and COT questions

[manxam]

In order to determine equivalent AFR including PE and COT, one would just make a custom pid of [SENS.121]/[PID.68] correct?

Also, my truck's cat temperature is 1200+ at idle and rises as high as 1650 during driving. I have raised cot by 200 degrees on the 3 thresholds but that still means 1215, 1180, 1165 degrees.

I assume that means it's ALWAYS in COT.

Is it safe to raise this another 200-300 degrees or just disable it all together?

Thanks

[manxam]

Ok, my fault.. Disregard the COT question; Logging in Fahrenheit, tuning in Celcius

[EC_Tune]

Why not use Commanded AFR? Normal driving it's 14.6x and at WOT it's less than that.

If you only have EQ ratio and are using a wideband just make a custom PID for the wideband which is (14.7/wideband AFR)

[manxam]

My commanded AFR ALWAYS shows 14.7 regardless of TPS % or PE. I've logged several times (~30 minutes at a time to and from work) and I've never had a value other than 14.7

I had assumed I was doing something wrong as is why I figured maybe I had to take the commanded value and divide it by whatever value PE/COT was currently at.

Hrmph..

[EC_Tune]

You may not be going into PE. Check RPM & Torque% settings. Drop the RPM setting to ~600 and Torque to 0%. Then you will go instantly into PE when you meet the MAP & TPS qualifications.

Usually when you startup from cold you get something else other than 14.6x as a commanded AFR. May want to check that. You will only get a few seconds at idle before closed loop enables though.

[manxam]

I'll post a log, stock config, and altered config in the morning if you wouldn't mind checking them out. Even upon startup i'm only showing 14.7.

For the histos/log config I'm using your custom ones referenced in another post re: the I5 motors for tuning VE.

Thanks for your time EC!

[manxam]

You're right, for some reason it was never entering into PE.. I have subsequently modified my config and all appears well!

I've included my configs for you to look at anyways to make sure I'm heading in the right direction.

Also, I was stupid (and cheap) and didn't order the EIO version of the cable and now wish to utilize my wideband but don't have the cash to upgrade the cable.

This vehicle has no EGR so i can't utilize the trick of wiring the wideband through the EGR.

Is there a way to wire the wideband in place of my second O2 and get HP tuners to recognize the additional voltage and log it appropriately? I've seen mention of it but no details.

Thanks again.

[EC_Tune]

Check the I6 wiring as *I think* they use the same controller. Not sure though if the I6 has EGR... If not it was a nice thought... lol

Any I6 guys to verify this?

[Canyon04Z71]

Check the I6 wiring as *I think* they use the same controller. Not sure though if the I6 has EGR... If not it was a nice thought... lol

Any I6 guys to verify this?

All the GM I-engines now use an exhaust cam to replace the external EGR.. The exhaust cam allows overlap of intake/exhaust to provide an internal EGR function.

If you remove the second O2, you will not pass an emissions test, atleast not in my state. Other than that, it is just there to test the efficiency of the second catylitic converter.

The PE delay was prolly keeping you out.. Something like 10 second delay before going into open loop if that is enabled by RPM. From the factory it is enabled upto 8000 rpm, so all the time.

Jack the Piston Protection to 6500 rpm to take it out of the equation and lean out the commanded AFR in open loop, IMO. Looks like you already upped the COT thresholds, what are you seeing for "exhaust temps" during WOT and cruise? That will determine how much you need to adjust COT stuff.