New owner, SCT, questions/opinions/verifications...

[ezdubbin97]

Hey guys, bought an 05 CC a few months back, and slowly been making progress in the 'empty my pockets' small modifications to the truck.

My biggest concern after purchase has been the MPGs, which sat at 10 or less when I bought it. To improve it, I went through the basics: oil change to Rotella T6/Rev-X, changed both fuel filters, changed out to blue spring, ran Diesel Kleen, & changed air filter (had a TruFlo drop in that looked like someone used it to filter pond water). Seemed to pick up a MPG or two from hand calculations. Next on my agenda was to purchase a SCT LW tuner to run on an performance tune while keeping my foot out of it (easier said then done)...upon purchase and monitoring I've found several interesting tidbits.

First off, truck has always had a longer then usual crank time (hot or cold)...the batteries date code to 2005, so best to assume they are original. SCT shows voltage at around 11.5V after glow plug warm up, and goes to 10.xxV while cranking. Guessing battery replacement = quicker start?

Second, I have been using the Livewire to monitor ECT/EOTs. No big temp difference between the two, they actually like to stay pretty close together once warm (peaks of ~8* while driving), however, the ECT is most comfortable @ 178*, barely capable of going above 180* (will get there driving hard, but stays for mere seconds). Guessing thermostat is shot and replacement will pick up a few MPGs.

I also show code P0673 for glowplug #3, should I swap or test? Cleared it, but it does come back as my only code (no CEL).

Wondering from the community, is there anything else I should monitor or recommendations for testing/preventative maintenance?

[Lilpooh]

Get them batteries replaced ASAP, weak batteries can cause issues with the FICM and injectors.