Hello all

Intro

I run a 8D0 907 551 K from RS4 B5 on a S4 B5 with D-Box.

All hardware from the S4 B5 is stock except downpipes are without precatalyst only with main catalytic converter.

Problem
After a ride with some full throttle pulls, two errors are stored in the ECU. P1131 & P1113 Internal resistance too high - sporadic. Both error messages relate to the 1st O2 sensors (not to the 2nd O2 sensors).

Details about changes I made
I have executed the instructions according to S4wiki, which are listed in the chapters Rear O2 ESKONF and Cat and O2 complete removal and DTCs with the exception of CWKONABG. I have set the value for CWKONABG to 1 rather than 0 so that the idle speed is increased at cold start.

In detail I have changed the following:














Question
In my opinion, my changes have no relation to the two error codes P1131 & P1113 for the relate to the 1st O2 sensors. And it is unlikely that both sensors will break at the same time. So my question: is there a threeshold that needs to be adjusted for the O2 sensors in the K-Box file because the O2 sensors from the S4 B5 are used instead of those from the RS4 B5?

Your front sensors are bad.
Possibly they were damaged when removing the pre-cats.

Replace both front sensors.

If problem persists, start searching for bad grounds.

Why you would run 551K RS4 software in an otherwise near TOTALLY STOCK S4 is beyond me. Cams/heads don't match, CR doesn't match, intake manifold model doesn't match, inlets and turbos don't match, injectors don't match. You'd be FAR better off putting a map pack together for your D box and tuning that rather than trying to reinvent the wheel on software that was intended for a totally different engine.

Just my 0.02 worth of over 1000 S4s and 500 RS4s tuned in my life.

Hi IamwhoIam

Thank you for asking.

I have already tuned the vehicle with a D-Box software. The reasons why I now use a K-Box software for the D-Box from the S4 B5 are the following:

1. I want to get to know the ME7.1 even better. If I use a K-Box software on a S4 B5, I have to adjust much more than it is the case with a D-Box software. This way I get to know the ME7.1 better and I find my knowledge gaps.

2. I still have a RS4 B5. Tuning an RS4 B5 with a aftermarket ECU is no problem for me. I have implemented a polyoctane software with flexfuel capability from scratch (with all stuff, handle coldstart and hotstart issues and so on...). But I am still far from being able to do this with a ME7.1. My goal is to increase step by step my knowledge that I can tune my RS4 B5 also with a ME7.1. Tuning a S4 B5 with K-Box software is one of my steps to achieve my goal.