I have been trying to find out what are the voltages of the MAF sensor in the Ecotec motor..the check engine is not chucking any codes.. Before I start replacing the MAF and Oxygen sensors I'm just wanting to know if anyone knows the stock values when the motor is hot.. At idle mines 4.32 volts and as I increase the throttle it drops to mid to low 3 volts.. If anyone is bored has the multimeter around I'd really appreciate it if they can reply with there values from the Ecotec MAF.. I inserted a paper clip into the back of the plug so I didn't need to cut wires.. Cheers guys.. The story so far.. The car has a bad thudding under load only once it's starts to warm up.. It's fine for the first few ks..then once it warms up its thumping away and lacks power.. It's shown to retard timing and run rich when this happens.. I have been advised replace the MAF oxygen sensors maybe also the knock sensors as well.. I have just had the inlet manifold gaskets done, new plugs and leads and tried another set of known working coil packs all 3 and another DFI module and that's made no difference.. So it would seem if it's a sensor it would be one that shows a open loop cold the once warms it creates the thudding.. I know I have just posted but I have now spent over $700 and no improvement bar the fact I have no oil in the coolant now..