I might get one of those, but I'm not going to stop suggesting this test. Not everyone is going to have one of those handy, and the screwdriver method is not as "old-school" and universally frowned-upon as you suggest.

"Remove the spark plug wires one at a time and insert a small screw driver into the wire.(SEE WARNINGS) Be careful as you don’t want to get shocked with 60,000volts. Hold the wire so that the screw driver is 1/8” away from the engine. Have someone crank the engine and watch for a good white spark. If you have a good spark on all wires look for a problem with timing or something else".

http://www.wikihow.com/Diagnose-a-Lo...our-Car-Engine

"CAUTION: Secondary ignition voltage can shock you. Do NOT hold or touch a spark plug wire while cranking the engine.

If your engine has spark plug wires, disconnect one of the plug wires from a spark plug and place the end of the wire near a metal surface on the engine. You can insert a small Phillips screwdriver into the end of the wire (the plug boot), or a small bolt or nail to provide a conductive path. Then crank the engine and look for a spark to jump from the screwdriver, bolt or nail in the end of the plug wire to the engine. If you do not see a spark, there is an ignition problem".

http://www.aa1car.com/library/no_spark.htm

Finally, I offer in my defense the "Blackhawk Spark Detector Screwdriver":

http://www.stanleyproto.com/default....or+Screwdriver

Handheld, for testing secondary ignition.

 

If the cat "is empty", you may have a cracked head. Depending on how long the plenum has been blown and when the cat was gutted.

 

Merc, I do appreciate your finding me a source for an adjustable spark tester. The eight-cylinder tester seemed a little cumbersome, with the need for additional extension wires and all, which themselves could become suspect over time. The manual also said it couldn't (or shouldn't) be used with the engine running, but this one (also by CDI) can be, and is a lot simpler - one cylinder at a time. At $18.95, I'll get one.

CDI 511-9763 Adjustable Spark Tester



http://www.marineengine.com/newparts...um=CDI511-9763


But again, for those who don't have one of these, I will still recommend the screwdriver test, if they're disinclined to order one and wait for it to come in the mail. And the screwdriver test is still easier, and just as effective.

 

Cat was gutted back in march and I been fighting this code since june the oder has been since last month when I did the injector

 

I do the screwdriver test when I gotta test spark. I once did it for the coil wire on a '91 S-10 Blazer, wasn't too bad.