Missfire, No Code

[Mulbers]

Afternoon,

 

I've had my Z (2003 GT 69k) a month or two now and I have notice it has a missfire when at idle. Ever so slight, I can just feel it hiccup. I took a punt on an ebay special EML327 to try and find a fault code. Nothing came up. I don't know if that is because of the equipment and app (Dashcommand) though.

 

I've also noticed when after having a spirited blast I can smell sulphur dioxide. Is this because of rich running, knackered CAT, the missfire or just how they smell when rather warm?

 

I need to narrow these things down to find the fault. Any input would be greatly appreciated.

 

 

All the best.

[Ekona]

Check for possible exhaust leaks underneath, right from the manifold all the way back. That could well cause the smell, and it may be causing a hiccup that could be interpreted as a misfire.

 

I only say that as it's very unlikely to get a misfire with no code, especially if it happens regularly enough for you to notice it.

[GMballistic]

^^ What he said.

 

When my 350 was misfiring it through up the EML straight away. Traced it back to a faulty coil pack ~ replaced the coil pack, reset the ECU and happy days again.

[cs2000]

If you're pushing it hard you still shouldn't be able to smell the cats, the car behind you may very we'll be able too but not you.

[rtbiscuit]

if you are getting a sensation that feels like a missfire but no fault code i would suggest looking to see if you have a vacuum leak somewhere.

 

if you have an air leak after the MAF or on a Vacuum hose it can give a lumpy idle and not throw an error code.

[Mulbers]

if you are getting a sensation that feels like a missfire but no fault code i would suggest looking to see if you have a vacuum leak somewhere.

 

if you have an air leak after the MAF or on a Vacuum hose it can give a lumpy idle and not throw an error code.

 

Thanks for the reply. I will check this out over the weekend.

[M13KYF]

plenum leak possible,