true, S1 is prone to failure, but still a LOT of Z32's running round with them installed. Is a recommended upgrade, especially considering failure can be without warning and leave you stranded. I ran 7 years with a S1 PTU without fault, and was still working perfectly when I changed over.
Series 1 Power Transistor Unit Series 2 Power Transistor Unit Otherwise known as ignition module, controls delivery of spark to plugs (sort of like a modern replacement of the distributor). Series 1 were found to be prone to failure. This can cause the engine to completely stop, or sometimes worse run poorly for years without being diagnosed. Some people who have replaced it with a series 2 without thinking they have an issue have reported big improvements.
If you have the S1 PTU, it would be good to replace it with a S2. Many people still have a S1 ptu and done 200 000km+, but alot have changed to a S2 as a preventive and noticed a great improvement in idle.
as everyone says s1 is prone to failure, but you got to remember.. they are 20 years old, 20 years for a s1 is not bad. if you do change it with a new s1.. and you get another 20 years out of it..... in the US, the s1 ptu's where recalled and they where all upgraded to s2..
