High AFR value

[Ram Air IV]

I have observed that the AFR on my car has changed the last days. Earlier that the WB show a AFR of 13-15 under normal load. Now the AFR value is 17-18 (max). What could cause this? Clogged injectors or some other things. Unfortunately I don´t get any DTC and with such high AFR should I get a DTC for lean bank 1 or 2 or both? I Have attached a short logg file. Is there some one who know what I should look for.
Magnus

ps I have also observed that the fans runs more often. ds

[andysc3]

Mine had a similar issue. Turned out to be an exhaust leak. Post up your tune.

[Ram Air IV]

So here is the tune.

[joecar]

+1 check for leak in exhaust header.

[Ram Air IV]

With a bottle of STP injection cleaning and 200 km of driving it is back to normal AFR (14-15), Placebo effect ?

[Tre-Cool]

or a loose spark plug lead. cyclinder not firing etc can still result in a lean idle.

[joecar]

+1 correct, a misfire causes a lean condition (unburnt oxygen).

[Ram Air IV]

Thanks all, I will have my eye on the WB lambda.

[joecar]

With a bottle of STP injection cleaning and 200 km of driving it is back to normal AFR (14-15), Placebo effect ?This may have temporarily cleaned up something (injectors, valves, O2's).