Originally posted by Gerry_M:
Read: you need to stick in a can of 'Catalytic Converter Cleaner' into your gas tank AND/OR a can of 'Berryman's B12' or 'seafoam'.
You'll need to do this for, probably, 3 or 4 fill-ups before the CEL completely stops.
This is a 'progressive' (albeit cheap) fix.
Worked for me ...now going on TWO years since I got the 420 code ...(I swear by Berryman's B12!) -- and was a lot 'cheaper' of a fix than going the $tealership route. ....Oh yeah, btw, splash out for a code scanner -- try ebay -- it'll 'save' you from having to pull fuses or disconnect the battery every time the CEL comes on.
Also, do NOT drive with the CEL on! ...the car goes into "limp home mode" and ENRICHENS the mixture -- further exacerbating the problem of 'semi-clogged-cats'!
The B12 won't work if the pre-cat is past the point of no return. I tried the B12 (5 tankfuls) 6 months ago. Was good until a few weeks ago when P0420 came every week(and 430 came every 3 months or so). Gave up and went to mileliminators last week (Thanks Chongo for your post on mileliminators).
"Always do the cheap and easy ones first."
1996 V6 ATX 96K miles
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