r6cavy

Ok
so I had a p0430 code on stock cat with 80k I then changed to 200 cel cats and got both p0430and p0420 codes with all new sensors. So it was suggested I change the sensors as they may be defective. No dice.. still threw code. So I put some o2 spacers in. Nothing fancy. Just chose the smallest diameter insert. Now only getting p0430. So I got a durametric and did a crappy job of recording. Anyone tell me what’s going on. This is at idle. I went for a 20 min drive but let it sit for 20 mins after while I got my laptop out etc.

De Jeeper

200 cel cats r known to through those codes. U probably need o2 bung extenders to "fool" the system. This issue is pretty well documented here.

jumpy chunky

Your Durametric readings show a rich fuel mixture entering the converters. .45 millivolts shows a well blended fuel air mixture.
Post cat sensors show one converter not doing the job. Check your fuel trims to see what might be the concern.

r6cavy

Thank you
heres my fuel trims. I was told in a different post they look ok. I’ve added o2 spacers to the cats.. short t straight ones with smallest insert. Don’t seem to be doing anything. I’ll be chsnging out the plugs and I ordered fabspeed mini cats hoping this will fix the issues. Will install new plugs first and re check before installing mini cats. Watch...I’ll prob end up putting good stock cat back on and looking for bank 1 cat that’s still good.

yelcab

It's been my experience that good stock cats beat all after market non-sense when it comes to CEL codes, and extenders, and minicats.