p0300 and p0420.."clogged" cat..random misfire?
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Codes just popped up over the weekend at the same time (no previous DTCs) but the car seems to run fine. I'm confused as to how these codes co-exist? How does the cat cause a "random misfire?" Wouldn't be too disappointed if I needed to replace the cats, looking to open up the exhaust from the cats to the back. Any input or previous experiences with the following codes? Everything I searched had multiple DTCs, these are the ONLY two popping up for me..
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Codes just popped up over the weekend at the same time (no previous DTCs) but the car seems to run fine. I'm confused as to how these codes co-exist? How does the cat cause a "random misfire?" Wouldn't be too disappointed if I needed to replace the cats, looking to open up the exhaust from the cats to the back. Any input or previous experiences with the following codes? Everything I searched had multiple DTCs, these are the ONLY two popping up for me..
P0420 set because PCM determined that oxygen storage capabilities of the
converter has degraded below a calibrated threshold. Bank1 or driver's side cat is ineffecient or worn out.
P0300 random misfire even though your not noticing it, the PCM is picking it up. You could try a spray bottle and wetting down each plug wire individually to see if you detect misfire. If that works you could narrow problem down to what cylinder, but if not lot easier to diagnosis with a scan tool by looking at misfire counters.
Chris
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Appreciate the input. I have new plugs/wires already so I might as well throw those on and see where it takes me. Any other possibilities for the p0420 code or should I just expect to replace the cat?
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Not sure who Alex is, but the issue was a bad cat. I went with longtubes/ORY and it solved the problem after the tuner corrected everything. If you're on a budget, have the cats gutted and have someone tune them out and you'll be good to go.