ECM or PTU

[canuckj30]

Need some help people. The story goes like this:

My car started misfiring yesterday.

Diagnosed the problem to thethe no.5 cylinder.

Coil pack is good, plugs are good and compression is good.The car has approx. 192k kms.

Plugged a noid lamp into the harness connectionto the injector and......nothing.

So what can it be? Power Transistor unit or the ECM?

Any advice would be appreciated

Thanks in advance

[goody90q45]

If it was a power transistor wouldn't the whole bank of cylinders be down (1/3/5 or 2/4/6)? I'm not sure what a noid lamp is but try oming #5 fuel injector directly off the injector if it's accessible or through the harness if the injector can't be reached.