GMC Terrain, Equinox, and SRX Forum banner
21 - 32 of 32 Posts

Registered
Joined
28 Posts
Hey, is this cat still ok?
Wood Gas Auto part Artifact Font
Automotive tire Wood Synthetic rubber Rim Carbon

That's part of the O2 sensor (now removed) in the top right corner.
I have to thank the techs at the garage who worked on my car for the pics I've been posting.
 

Registered
'16 Equinox LTZ AWD 3.6
Joined
1,564 Posts
It may be OK, only way to tell is putting in new sensors and see what turns up.
That's why sensor should be changed when plugs get changed.
 
  • Like
Reactions: christopherlompoc

Registered
2010 chevy equinox lt 2.4, 135k miles. Mocha steel metallic mobile 1 full syn extended performance
Joined
1,005 Posts
Try cleaning it now that it's off too make sure its all clear. I actually think thats toasted.
 

Registered
2011 Terrain SLT 2.4L FWD
Joined
73 Posts
Hey, is this cat still ok?
View attachment 18183 View attachment 18184
That's part of the O2 sensor (now removed) in the top right corner.
I have to thank the techs at the garage who worked on my car for the pics I've been posting.
You should have uploaded higher resolution pictures, but I'd say you're burning oil. Your cat screen should look grayish, not black..
You should stick a light in the other end and see if you can see through the screen.
You can also try holding the cat upside down and burning off the carbon with a propane plumbing torch.
If you're burning oil, then this will likely happen again, and next time, sooner.
The other thing is to make sure the engine is running well otherwise, because if your computer isn't getting the correct information from all the sensors it uses, it will likely have the engine run too rich, and that's a big problem for your cat since the cooler exhaust temperatures won't burn off the deposits from the cat screen like a proper running engine with a leaner mixture and hotter exhaust.
 

Registered
2011 Equinox 1LT V6 3.0L FWD 174.6k miles
Joined
4,511 Posts
I鈥檓 reading and scrolling through this thread and up pops the funniest screen name I鈥檝e seen here (I think): @Equinox Plague

If you actually have the data, you should consider writing a Wikipedia page. We know when this Plague started, but it鈥檚 unclear at this time if it ended when GM said it ended.

And we really don鈥檛 know how many victims there were, either.
 

Registered
Joined
28 Posts
I thought it was burning oil even before the CEL. The cat is on the car now so it's a big deal to check again especially it's now winter. The mechanic who did that job was wary the cat was in bad shape too.

The engine runs really well I hope a new o2 sensor will stop the P0420 for at least a couple of years...
 

Registered
Joined
2 Posts
Below is a list of common conditions to set a P0420 DTC.
This was taken from the 2014 GM Service Manual for the 2.4L.


Engine misfire
High engine oil or coolant consumption
Weak or poor spark
Retarded spark timing
Rich or lean fuel mixture
Damaged O2 sensor or wiring harness
It was the resonator on my car I no longer get that code
 

Registered
Joined
2 Posts
Need some advice on where else to look for a problem that is throwing this code. I replaced both oxygen sensors with quality parts, and then I replaced the catalytic converter (the one that connects directly to the exhaust manifold). I also replaced the cracked exhaust manifold at that time.

Car still throws this code in a few days after I reset it. It has been recently rebuilt with new pistons by dealer and is not burning oil.

Any advice on where else to look for an issue?
I have a 2013 that was throwing that code and I did the same as you replaced the exhaust manifold, swore it had to be those darn 02 sensors. But what it turned out to be was the intake and exhaust (oil control sensor, variable valve timing solenoid) they are both the same thing. All I had to do was take them out and give them a good cleaning. I checked the voltage and the ohms ton make sire they were receiving power, then cleaned with maf cleaner put them back in and the code was gone. I did all the extra stuff for no real reason except someone told me they were sure that was what was wrong.
I ve learned now. Do everything that isn't going to cost anything ie. Check connections, clean parts, verify if possible the solenoid or sensor is working properly and by power of elimination you ll find the culprit of the code before you spend a dime.
Oh yea I did add seafoam
Need some advice on where else to look for a problem that is throwing this code. I replaced both oxygen sensors with quality parts, and then I replaced the catalytic converter (the one that connects directly to the exhaust manifold). I also replaced the cracked exhaust manifold at that time.

Car still throws this code in a few days after I reset it. It has been recently rebuilt with new pistons by dealer and is not burning oil.

Any advice on where else to look for an issue?
I did the same as you spent time and money I didn't have to. I found that the intake and exhaust (oil control solenoid, variable valve timing solenoid) both are different names for same thing. Just needed to be cleaned. Make sure and check the continuity and ohms to make sure they are working properly then clean them with maf cleaner and put them back in. I did also use seafoam deep penetrating additive in both the gas tank and the oil to get rid of any gunk build up and wha..LA the pesky engine light went out and the code was gone. Hope this helps.
 

Registered
Joined
1 Posts
Just replaced my 2017 Equinox 2.4L engine with a remanufactured one along with new sensors and new cat. Right around 300 miles into break in of the motor, the 0420 code came on.. called the mechanic that did all the work, which is a reputable and good mechanic so there no question as to his work, but he is unreachable currently so... the check engine light came on right after fueling up and getting back on the highway. Problems I'm needing to get the car emission tested so I can get it registered and all that but don't even know where to begin since literally everything is brand new and just replaced less than a month ago. Any ideas or help would be greatly appreciated! Thank you!
 

Registered
2011 Terrain SLT 2.4L FWD
Joined
73 Posts
Just replaced my 2017 Equinox 2.4L engine with a remanufactured one along with new sensors and new cat.
READ THIS POST:
If you've checked everything I mention in my earlier post, then you may just need a new downstream O2 sensor, or a new catalytic converter. But you don't mention how many miles you have on the cat, or why you replaced the engine in the first place.
 
21 - 32 of 32 Posts
Top