my check engine light will not go off.i have disconnect the postive cable,to reset. it went off last year and then came back on. the problem occure is every day. i have two code p770. which is the soloneid switch sticking . i had aamco to replace it last year but it is still reading the same code. also the second code is p420. how do i pass my emission test
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2003 Toyota Corolla Question: check engin light on
Answer #1mastertech6371 July 22, 2010, 20:00Master
you need to have it fixed. get a diag and repair on the trans code and a shop for the code for the cat. clearing the code does not fix it. you need to address it before it becomes a bigger problem.
Answer #2patrick mannion from Greg Solow's Engine Room, July 23, 2010, 00:20Master
P0420 is low catalytic converter efficiency. It is an expensive code to fix. Usually it is a sign that the cat. convt. has got lazy but it is sometimes a O2 sensor/air fuel ratio sensor problem.