After reading a number of positive and negative accounts of decatting on the following threads;

http://www.300zx.co.uk/forums/showthread.php?t=74882&highlight=decall

 

http://www.300zx.co.uk/forums/showthread.php?t=73579&highlight=decatt

 

I thought the way i would use to distingiush if decatting will cause me problems is...........

 

........Have you had problems with smoke due to turbo seal failure or turbo failure after NOT decatting. ie are these problems naturally occurring or have other causes other than decatting.

 

 

The other question I have is......if you have a car which has been decatted and is not showing signs of seal leakage (symptoms: smoke??) if you reinstall the cat will everything be fine and dandy and the turbos will last as long as they would if never decatted.

Turbo seal failure will naturally occur with age/mileage decatted or not.

 

Sometimes yes, putting cat back on will "hide" the smoke from seal failure. This is what happens most of the time when people decat. The cat that was previously hiding the smoke is removed and the car smokes. It will not fix the seal leaking though.

 

Turbos can last a very long time with leaking seals, and the degree of seal failure varies.

this topic is so over done

Interesting point you have there my west country friend. So in theory if a car is running smokeless with no cat it is the best test whether the seals and leaking, then wack the cats back in before the seals do go (depending on your whole opinion on the decatt debate).

 

However, are there any other earlier warning signs that show that the seals maybe on their way out before they start leaking oil into the exhaust gas.

yes, youl be going thru oil faster, and the CO/HC readings from the exhaust gas will be significantly different

if the cats are just masking the smoke, it makes you wonder how many folks turbos were blown before they de-catted