Help me with engine code...
#1
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Join Date: Jan 2010
Location: Always Bigger in Texas
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Help me with engine code...
Ok. so my 2001 ls is throwing a code. I own the actron OBD2 scanner from advance auto parts and the code that comes up is P0420. Reads "catalyst efficiency below threshold bank 1". The question here is...what the hell does that mean?? Im getting no funny driving feelings or sounds. Anybody got any bright ideas?
#3
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I have no specific knowledge of this problem on Miatas, but based solely on the code description I would think that means it's sensing excess fuel downstream of the cat. Could be that the downstream o2 sensor needs replacing, at least that would seem more likely than the cat itself failing. The term "efficiency" implies some comparison of pre-cat and post-cat sensor readings so I suppose a faulty pre-cat sensor might also cause that code. (?) Maybe also check for exhaust leaks. It doesn't sound like a code that would come with any real driveability issues so you're probably okay to keep driving it.
#5
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thanx guys. I also googled the code and found for myself the cat is done. I just replaced both my o2's less than a month ago. I suppose its time to replace the cat.. anyone got a place to find a cheap bolt in??
#7
I have no specific knowledge of this problem on Miatas, but based solely on the code description I would think that means it's sensing excess fuel downstream of the cat. Could be that the downstream o2 sensor needs replacing, at least that would seem more likely than the cat itself failing. The term "efficiency" implies some comparison of pre-cat and post-cat sensor readings so I suppose a faulty pre-cat sensor might also cause that code. (?) Maybe also check for exhaust leaks. It doesn't sound like a code that would come with any real driveability issues so you're probably okay to keep driving it.
#8
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If you just replaced you o2 sensors then I agree with you... the Cat is done, probably got polished off from the way it was running before you changed the sensors.
Take a look at highflow cats offered on here by the sponsors, could be a worthwhile upgrade and cost less then a new one.
Take a look at highflow cats offered on here by the sponsors, could be a worthwhile upgrade and cost less then a new one.
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