Hi I have a problem with my gc8 face-lift with it miss firing. Iv had the car lying for about a year not doing much. Iv started to get it going again and so far iv replace the coilpack leads and mass air flow with the diagnostic saying its the mass sensor. Its cleared on the diognosis bus still missing. All parts are genuine resulting in the missing not being so bad but still missing. Iv got spark plugs coming but the ones I have in are quite new. I would be much obliged if I could get some recommendations

Thanks

 

Possibly bad fuel if it's been sat for over a year?
What year/model and is it standard?
Also check pipework for splits etc

 

I put a half tank of fresh in. May be I need to give it a good run? It gets worse the more throttle you give it. Its as if its struggling to run at full throttle. I'll give it a decent run tonight and see if it gets any better.

 

Yes it's standard and it's a 99 with 116k

 

Maybe the 02 sensor, but I guess that would of flagged up on the diagnostic.

But I agree with ossett2k2, reckon its because your car has sat around for a year.

 

Also any fuel trims and knock control tables will have been reset so giving it a good run would see the car run better.

 

Yes mate, I think your car maybe just needs a good run, and hopefully all shall be good for you