Toyota Repair: 98 Camry V6- Spark Plugs and Code 0420, 67 cougar, camry v6

Question
Ted,
I've seen your responses regarding the P0420 code and will look into having an aftermarket cat installed. Some one mentioned I should change the O2 sensors and plugs first as the car has 165K on the originals. How do you recommend to get at the $## back 3 plugs. I thought the plugs on my 67 Cougar with a 428 and custom headers were bad. I guess I'm getting old.

Thanks,

Kris

Answer
Replacing the spark plugs will not do anything for the PO420 code and in most cases replacing O2 sensor won't either, O2 sensor failures will normally set a different code, the 420 is specific to the cat converter's efficiency. Those spark plugs can be removed in two different ways, by removing the intake chamber or by using an array of extensions of different length and a swivel extension and a swivel spark plug socket and a ratchet, if you have plenty of time use the first method, we use the second method because of time concerns and we don't get paid to remove the intake chamber.