Ls1 pinging and oxygen sensor issues

**Exec57l** · 08-23-2012, 01:23 AM

Hi guys,first time posting here, hoping someone can help me with a long term issue I have been having with my ls1.
I own a 1999 ls1 powered Holden commodore with t56, similar to the car badged as a pontiac in the USA.
I have owned the car for many years and have always had issues with pinging here and there and oxygen sensor faults, being low voltage faults left and right bank.
The only mods to the car are a cat back exhaust and a tune, however the car used to do the same with the factory computer before the retune.
Has anyone got any suggestions re the oxygen sensor faults and pinging? The car does use a little bit of oil as most early ls1 did out here and it goes great when cold but at operating temp it seems to get worse.
Have changed plugs,oxygen sensors multiple times,checked fuel pressure etc and nothing improved.

Have been looking at possibility of oxygen sensor earthing lately.

Any suggestions appreciated.

Thanks

Paul

**2NDSLPSS** · 08-26-2012, 02:10 AM

pinging, . . . detonation could be as simple as slightly too much timing, or not high enough octane fuel. most simple route would be to try running a better quality fuel.

Then....as im sure you know your oxygen sensors may effect your a/f. and an issue with these may very well be the cause of your pinging,oxygen sensors send a very fine voltage curve as most sensors do. considering you have changed sensors with no change in symptoms i would start looking at the harness above the connector for the sensors. check the connector itself and the harness as far as you can trace it looking for burn marks, hot spots, frays, or anything of the sort that could cause an issue with the voltage curve. what exactly was the code your getting ?

**Exec57l** · 08-26-2012, 05:05 AM

Originally Posted by 2NDSLPSS

pinging, . . . detonation could be as simple as slightly too much timing, or not high enough octane fuel. most simple route would be to try running a better quality fuel.

Then....as im sure you know your oxygen sensors may effect your a/f. and an issue with these may very well be the cause of your pinging,oxygen sensors send a very fine voltage curve as most sensors do. considering you have changed sensors with no change in symptoms i would start looking at the harness above the connector for the sensors. check the connector itself and the harness as far as you can trace it looking for burn marks, hot spots, frays, or anything of the sort that could cause an issue with the voltage curve. what exactly was the code your getting ?

I have always used 98 octane fuel which is pretty much the hihg octane pump fuel we get out here and doesnt make a difference, tried different brands and always dramas.

The fault code was low voltage (o2 sensor left bank) and low voltage (02 sensor right bank).

I am looking at possibly an earth problem to 02 sensors, oil usage contaminating fuel or timing at the moment. I have used two computers, the factory one and a tuned one and both had the same issue. The most frustrating thing is that it doesnt do it 100% of the time and absolutely screams when it is cold.

**2NDSLPSS** · 08-27-2012, 08:22 AM

have you pulled a plug and checked its color ? oftentimes you can tell a lot about how a car is running by the color of its plug, ie. white on the ground strap = too hot, black = oil consumption or too ritch, nice even tan color=good. that may tell you what you are looking for. i chased my rear for a long time to find out that had a coolant leak in my intake manifold and the glycol in the coolant that was being "misted" into my cylinders causing simular isssues