Unexplained 100mi/tank drop! '03 civic HX

[FastFebur]

Cleaned out the EGR last night and replaced the gasket.
Wasn't too alarmed at the condition. Not a lot of buildup at all.

[Xist]

Was this the first time you cleaned the EGR? Mine was blocked at 190,000 and I had a code.
Have you made sure the oxygen sensors work correctly and you enter lean burn? I have always read that only NGK\NTK ones work, but sometimes new ones are bad.

[FastFebur]

Yes, this was the first time i've cleaned out the EGR. I was expecting a little more buildup actually lol.

I haven't checked as to wether the o2's are working correctly. I've put on more than 5kmi since installing them and haven't had a code.

I'm not familiar as to how to determine if i'm going into "lean burn". I've got a trust innova scan tool. What should I be looking for?

[Xist]

Unfortunately, that information is not here: Lean burn - EcoModder

From what I have read, you often feel something like a misfire, and power output is reduced. I believe it is supposed to burn cooler and if you have an instantaneous gauge it would actually show increased fuel consumption because only the MPGuino measures fuel, everything else measures airflow and does math. I am not sure what else, nor what a code reader could tell you.

I was hoping someone else would step in.

[Piotrsko]

What know ( not much) exhaust temp cooler O2 sensors cycle slower anti knock system backs off spark couple degrees, pulse width of injectors gets skinny, all which an be seen on typical scantool.