Over the course of about 4 or 5 months, I kept tripping a CEL P0430 about every 3 or 4 weeks, especially after taking it on a longer trip (over 100 miles). I'd clear the code and sure enough it would come back.
After looking at nearly every post about this code, I found one that suggested that you check the gas cap and check for cracks in the rubber O-ring. Yep, mine had about 10 - 12 cracks in it
I got a new one from Pelican Parts for $15.50 including the pop rivet. (There are threads about how to remove the old pop rivet and for installing the new one.)
1000+ miles later and I haven't tripped the P0430 code once. Sometimes the problem isn't a big one or an expensive one. If I trip this code again soon, I'll be looking to replace some O2 sensors. Until then...
