my check engine light is on what is the problem? on 1996 Toyota Land Cruiser

i used a hand held diagnostic machine to check it and the code that came back was PO420. please get back to me asap

by in Rochester, NY on January 07, 2012
2 answers 1 comment
ANSWER by , January 07, 2012
P0420 is low catalytic converter efficiency.Could be a bad cat, false O2 sensor readings or have failed due to an out of tune engine/excess fuel or misfire.
COMMENT by , January 07, 2012
thanks again,what are you suggestion first?
ANSWER by , January 07, 2012
Use a scanner that can provide you with rear O2 sensor readings. If you have a smart phone there is a wonderfull new piece of equipment for $99.99 that can provide you with this info. Go to to see. I really can't believe how good the device is. Of course it comes from silicon valley. The truck is 16 years old. You most likely have to replace the cats.