Detailed Problem, Any help appreciated.

[786Nazir]

Hi everyone, I hope someone can participate in this.
I frigging love this car and this problem is making me pull my hair out
Car is a UK Civic Type R. K20a2
Meticulous maintained service schedule.
I hardly ever abuse the engine
Stock exhaust.
Gruppe M Intake.
Hondata Kpro Ecu - Running a Slightly modified K manager tuned base map.(Been running for around a year)
Two audio amps?

I monitor my fuel consumption fairly accurately, Sometime earlier this year (June 22nd) i noticed a significant drop in mpg during my normal driving style, The drop was around 20%. Drop was INSTANTANEOUS not gradual and i can recall the day/trip.
So far iv investigated and serviced the following...
Brakes all round, tire pressure, oil, air + oil filters, spark plugs, PCV valve, gas cap(?), and different fuel station.
Also carried out a compression test came back 160 psi +/- 10% across the cylinders with no major deviation between cylinders wet and dry.
(I think i did it wrong tho because iv never done it before)
I also disabled closed loop for two fill ups and the difference was negligible. Rules out O2 sensor?

So now i turn my attention to data logs and the ECU.
Attached are 5 data logs and the calibration.
Recorded in different ambient temperatures over the last couple months.
Data logs 4 and 5 have 7.5% fuel removed from column 3-7 as it is running rich, I'm not sure if this is inherent in the base map??
The car runs really good apart from this, power and responsiveness is great.
i get a slight hiccup after a gear change when driving calmly around 2000 RPM.

I think my next target area is gonna be the fuel system.
Have a look people let me know.

Naz.

[786Nazir]

Data logs Zip

[786Nazir]

Data log 4 and 5 are too big for standard upload but its pretty much the same as these.

[Spunkster]

That datalog has a long term fuel trim of -10 and that means it is trying to pull out a lot of fuel. I would recommend that you get this properly tuned on the dyno as you have said you are just using a basemap. It's also possible that you have a clogged cat.

[786Nazir]

Hi,
Thanks for the reply.
I think the map has had some dyno time by another owner but was remained in a non aggressive state. (back up or for friends).
I will get it dyno tuned at some point.

The thought of a blocked cat had crossed my mind along with a injector/fuel rail problem.
I am gonna invest in a vacuum gauge and a fuel pressure tester and attack these two areas next.

Wish me luck and thanks....

[786Nazir]

Slight update.
So i attached a vacuum gauge to check for exhaust restriction, it came back with a clean bill of health in all test.
Checked the fuel pressure and performed a leak test all come back positive and within spec. (45 psi constant).
I am gonna try replacing the injectors to see if that helps but they all looked really good (no leaks), although there is loud ticking on cold idle.

I am literally out of ideas only thing left unchecked is the transmission.