P0420 code issue
#1
04-24-2018, 01:11 PM
P0420 code issue
I just got a P0420 code - catalyst system efficiency below threshold bank 1. Will changing the down stream o2 sensor fix this issue?
2015 with 95k. Sometimes idles rough on cold start.
2015 with 95k. Sometimes idles rough on cold start.
#6
04-25-2018, 10:48 AM
On the DI engines the cat code P0420 is very likely to be caused by failed fuel injectors, in my experience.
One or two injectors squirting too rich can and will cause a cat failure code, and it can set that cat code without setting misfire or injector balance (trim) codes even when the injectors are the root cause.
Most of the time this requires replacing the injectors, then let the car go so we can wait and see if the cat code returns later.
The only scanner I know that can run the fuel injector self tests is the dealers HDS scanner
One or two injectors squirting too rich can and will cause a cat failure code, and it can set that cat code without setting misfire or injector balance (trim) codes even when the injectors are the root cause.
Most of the time this requires replacing the injectors, then let the car go so we can wait and see if the cat code returns later.
The only scanner I know that can run the fuel injector self tests is the dealers HDS scanner
#7
04-25-2018, 12:00 PM
On the DI engines the cat code P0420 is very likely to be caused by failed fuel injectors, in my experience.
One or two injectors squirting too rich can and will cause a cat failure code, and it can set that cat code without setting misfire or injector balance (trim) codes even when the injectors are the root cause.
Most of the time this requires replacing the injectors, then let the car go so we can wait and see if the cat code returns later.
The only scanner I know that can run the fuel injector self tests is the dealers HDS scanner
One or two injectors squirting too rich can and will cause a cat failure code, and it can set that cat code without setting misfire or injector balance (trim) codes even when the injectors are the root cause.
Most of the time this requires replacing the injectors, then let the car go so we can wait and see if the cat code returns later.
The only scanner I know that can run the fuel injector self tests is the dealers HDS scanner
Besides using the HDS scanner, are there any other symptoms I should be on the lookout for that would indicate bad injectors?
#8
04-25-2018, 06:59 PM
Wait til the code returns?
Besides using the HDS scanner, are there any other symptoms I should be on the lookout for that would indicate bad injectors?
IDK if reading spark plugs would give a clue, but it may be worth a shot.
Sometimes I see code P219A when there is an injector(s) overfueling, but other times not.
#9
04-26-2018, 08:55 AM
On the DI engines the cat code P0420 is very likely to be caused by failed fuel injectors, in my experience.
One or two injectors squirting too rich can and will cause a cat failure code, and it can set that cat code without setting misfire or injector balance (trim) codes even when the injectors are the root cause.
Most of the time this requires replacing the injectors, then let the car go so we can wait and see if the cat code returns later.
The only scanner I know that can run the fuel injector self tests is the dealers HDS scanner
One or two injectors squirting too rich can and will cause a cat failure code, and it can set that cat code without setting misfire or injector balance (trim) codes even when the injectors are the root cause.
Most of the time this requires replacing the injectors, then let the car go so we can wait and see if the cat code returns later.
The only scanner I know that can run the fuel injector self tests is the dealers HDS scanner
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michael.r.brog
2nd Generation (GE 08-13)
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09-24-2018 06:41 PM