Power Train light on; on L76 6L

[Checekiam]

Some of you have probably heard of this problem before. But bought a VZ SS 6L L76 12 months ago from a holden dealer, it has only done 35,000kms. When I bought the car the Power train light came on 3 secs after starting the engine and remains on. It has been back to several holden dealers and they say the same story it is an oxy sensor problem. However all oxy sensors (QTY 4) on VZ 6L have been replaced, still no fix. When holden replace them or swap them over it seems fine for about 30kms. The car has a cat back 3" redback system fitted. I am going to replace with headers and full stainless exhaust soon hoping it is a back flow issue. The exhaust guys told me this will not fix the problem. They seem to think it is the computer causing the code. Holden have assured me that there is no damage being done to the engine, it goes pretty well so do not think it is limp home mode or anything. Sorry to ramble on for so long but wanted to give all the info. Some help on this would be greatly appreciated.

[Kal123]

The same problem happens on the alloytec after installing an aftermarket exhaust, from what I understand, a vcm tune can fix this...

[bigdaddycool]

I think you'll find it's just messing with the O2 sensors.......... due to your exhaust. Bit hard to help you out without knowing the exact codes ur cars logging.

I have VCM Suite........ eg when I got hi-flow cats I got low cataylst performance warnings. I disabled them so no more "check powertrain" messages

[andyman]

the problem with the oxy sensors on the alloytec is when the cat converters are changed,

the 2 aft sensors behind the cat is designed to tell the computer the performance of the cat converters, it ensures they are burning the unburnt fuel in the exhaust,

do you know if the cat converters have been drilled or hollowed out?

if you have after market cats installed later on, you may need to get a tune, disable the aft sensors and remove them,

[bigdaddycool]

Essentially you need a fault read out as it could be anything