I'm trying to troubleshoot my brother's Subaru Wagon's absurd issue with a P0420 Code.
The Subaru has a Catalytic converter loss of efficiency code. Although it has a new catalytic converter on the car. had been replaced previously by a shop. I have a feeling the previous owner got hosed in this situation, and since my brother now has the car and its getting the same code again, I'm trying to track down all the other issues.
Somewhere along the line, the shop changed the plug wires over to an "STI" set of wires. Except this STI is for Spark Transfer International, a small company that produces "HP adding wires". Needless to say the wires measure in at 1/4 of there factory spec. I'm concerned that these things are causing either poor spark, bad spark, or RF interference.
Does anyone here on have experience with this? I've changed enough spark plug wires in my time, but never bothered to chance "performance" plug wires.
Factory spec are 5.6 Kohm to 12.x Kohm
His wires are 1.4 Kohm to 2.0 Kohm
Any ideas, suggestions? The car's engine runs well, but I'm not sure if the wires are aiding a solution to the problem and I would hate to have him buy new plug wires for no reason. The poor kid already put the money out for a pair of O2 sensors.
