Welloilbeefhooked

iTrader: (3)

It may sound odd but every now and again while cruising at around 80mph (where legally permitted) if I lift the throttle slightly I get a knock reading on the commander of around 45-50. Normally on full chat I don't see over 14.

The knock is a very sudden sharp spike that doesn't look like knock due to fuel or ign settings.

Occasionally I get a CEL that when investigated on the commander points towards the TPS.

So are the 2 related in anyway?

Wayne.

H4RDY-P1

iTrader: (46)

Sounds like the dreaded compressor surge ,do you get a flutter sound wayne on lift off?

Welloilbeefhooked

iTrader: (3)

Nothing at all mate. Would I get surge without it being on boost though?

Did you get knock with yours when you had the surge?

Welloilbeefhooked

iTrader: (3)

Any other thoughts?

Welloilbeefhooked

iTrader: (3)

Sorted it I think.

Its not compressor surge, its that my LC-1 O2 sensor needed a free air calibration. Once this was done the knock stopped. I'm assuming that the ecu was getting the wrong reading and changing the fueling causes the odd spike.

Anyway, seems fine now and the general knock reading on cruise is lower than it has ever been.

Wayne.

milothegreat2

How do you do a free air calibration?

Mines a stock MY99.

Welloilbeefhooked

iTrader: (3)

You need to have the LC-1 wideband kit. Its not something you do with a stock sensor.