Hi, there's something I can't fix for some days now. The problem is, occasionally actual AFR doesn't follow requested from the start of the WOT run almost up to redline. There's no lambda control when that happens - seems like open loop condition. Actual AFR does not follow BTS either, there are no part protection conditions and the logs show a lot leaner AFR than requested.
But when I compare two similar runs (one with the problem and one without), I see identical injector on time, engine load, etc. The only difference I see is actual AFR and lamda control. Is there something wrong with my O2 sensor or FPR or fuel pump (I'm still on returnless)?

Any help will be appreciated

Thanks

P.S. I read on the S4wiki that besides LAMFAW and LAMBTS there's LAMFAWKR for controlling open-loop enrichment, but I don't seem to have that on the ME7.5 (regarding the fully defined ME7.5 TT225 file too). Maybe there's another map for that?

Looks like bad O2 sensor

Bad O2 or you have an exhaust leak around the turbo area


Lee