Hello'
Hoping I can get some advice..i have a 2011 cruze 1.4 turbo with 153,xxx miles and cant get rid of this p0420 code. Ive had the up and downstream 02 sensors replaced, ive had the cat replaced and ive replaced the turbo. I dont know what could be throwing this code..im also getting the u0100 code which is ecm/pcm lost communication. Any insight would be helpful.
Thanks
I am having a similar issue. I've replaced both O2 sensors, the PCV cover, plugs, ignition coil, and the Cat. Drove the car around for about 30 miles and the CEL came back on with the same P0420 code saying the Cat was faulty. Has anyone figured this out?
Also having the same problem here for the past 40k miles with no luck. I'm tempted to delete the cats and have the computer tuned to ignore the downstream O2.
Anyone get this issue resolved? Had turbo go first, then egr valve, then 02 sensors, CAT and now water pump but the engine light is still on!!!!!!!!!!!!!!! Spent over $3000 on these repairs and beyond frustrated!
Ebay had some GM original cats for sale. My experience after market cats caused that code to pop up even though they are new. A premuim aftermarket might be okay but the cheaper ones cause problems.
It depends on how efficient the replacement cat is and how sensitive the rear 02 sensor/ECM is. Older vehicles you could get away with a cheap universal cat, but newer ones have to be good quality. Can't go wrong with OEM here. Otherwise you need a higher end aftermarket replacement. Also, make sure you fixed the problem that caused the original cat to fail as a new one won't last if the engine is still running very rich.
A code P0420 may mean that one or more of the following has happened:
Leaded fuel was used where unleaded was called for (unlikely)
A damaged or failed oxygen / O2 sensor
Downstream oxygen sensor (HO2S) wiring damaged or connected improperly
The engine coolant temperature sensor is not working properly
Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe
Failed or underperforming catalytic converter (likely)
Retarded spark timing
The oxygen sensors in front and behind the converter are reporting too similar of readings
Leaking fuel injector or high fuel pressure
Cylinder misfire
Oil contamination