Safe amount of boost to run on an S4

[KayGee]

One of those curious ones where behaviour changes as car comes on and off boost, when under vacuum will pull air in (lean mixture), when under boost will leak air out (rich mixture). Lean off boost, rich under boost.

Car runs lean and cylinder temps go up and up. ECU doesn't know as it is measuring a lesser amount of air at the MAF. The O2 sensors will record it's lean and attempt to adjust, but I'm guessing by not nearly enough.

[BRETTCOLLINS]

this air leak was before the turbo intake, So always pulling air in.

[KayGee]

Arghh, now I see, just after where the Y pipe splits and drops down the side of the engine to the turbo feeds. My mistake not paying attention, I thought it was where the turbo outlets fed back up to the TB.

In that case I'm curious why ECU/O2 sensors didn't register a fault as surely the ECU could see it was running lean all the time?

S2Tuner?

[BRETTCOLLINS]

LOOKS LIKE AMD HAVE DONE IT AGAIN.

think and I had problems.

I feel for this man

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