Black Sunshine

17514 O2 (lambda) sensor, B2 S1: vvoltage too low, air leak

16845 Fuel Level Sensor circuit: implausible signal

16558 Fuel Trim: System too lean, Bank 2, Terminal 30 missing

17658 Fuel Level too low, cylinder 1

Any suggestions??

It seems to throw different codes each time, first it was the TB pos. sensor (fixed that), then MAF signal too low now all this????

I just did an all new exhaust (replaced atleast one O2 sensor), then the ported UrS4 TB...

JWG

If you did not reset the ECU by disconnecting the negative terminal of the battery for at least a few minutes, your ECU will think that the car has not changed.

Actually, it's good you got the CEL's, otherwise your mods would have had no effect on air/fuel ratio and combustion. On minor upgrades, I purposely do not reset the ECU to see if I get a CEL, i.e., to see if the mod made enough of a difference for the ECU to notice.

By resetting the ECU, the ECU learns the new fuel/air mixtures by monitoring the various sensors for the first 20 or so miles.

Thus, upgrade the car, reset the ECU, then do some highway/freeway cruising for about 20 minutes.

Or so a fellow 12v owner who is also a factory-trained Audi mechanic told me. ;-)

Black Sunshine

So just unplug it anyways? Even since I reset the codes already?

JWG

Give disconnecting the "-" battery terminal a try--It's always worked like a charm for me.

Black Sunshine

so far no CEL but it usually takes it a day to come back on, sometimes two. And it's all new codes each time, sometimes a few of the sort of secondary codes are the same, but they are more the effect not the cause