Symptoms of P0421 OBD II Trouble Code
- The catalytic converter is no longer functioning properly
- An oxygen sensor is not reading (functioning) properly
- A sparkplug is fouled up
Common Causes of P0421 OBD II Trouble Code
- warm up catalist insufficent in bank 1 P0421I have a 2006 mitsubishi lancer es and i keep getting this trouble code that pops up. I am not sure if it is powertrain or what it is but no one locally can tell me what it even means. Ever time i have it run on a diagnostic tester I get P0421 "Warm up catalist efficency below thresh hold (bank 1)" ...
- P0171 and P0421 on 97' Mazda 626Hi there,
Last week I bought used Mazda 626 from 97, 2.0L, automatic transmission and about 97 Km. There were two things wrong I knew while buying, first, the exhaust muffler should be replaced, second there was the evil "Check Engine" light on.
Supposedly, as previous owner says, that has someth...
- CODE P0421 ON MAZDA 626I HAVE A MAZDA 626 WITH ONLY 67,OOO MILES. THE CHECK ENGINE LIGHT IS ON AND WHEN I TOOK IT TO AUTO ZONE FOR TROUBLESHOOTING THE CODE WAS P0421. DEFINITION-CATALYST EFFICIENCY LOW-BANK 1. EXPLANATION-THE OXYGEN SENSORS MONITOR THE CATALYTIC CONVERTERS ABILITY TO STORE OXYGEN. PROBLEM CAUSES- 1. CATAL...
- Mazda Premacy 2001 1840cc P0420 and later P0421I own the car about 10 years.
at the garage I usually do the maintenance I was told that this is a wrong indication about the Catalyst System,
and for years the car passed successfully the authorities annual test-so it is functioning OK.
They recommended to leave it as is.
Now there are new regulat...
- 2005 Jeep code of P0421 what is it what needs to be fixedHave Jeep wangler giving code of P0421what is this code and what needs to be fixed to correct it...
- P0421not a question but just thought I'd post this for anyone having the same code P0421 come up with no resolve. turns out a faulty/malfunctioning fuel sending unit can cause error P0421 to occur :) just changed mine and everything read perfect!...
- 2004 Mitsubishi Lancer OZ Rally P0421Ok so My Mitsubishi lancer 2004 oz rally passed smog last year then 6 months later I got this check engine light. I checked for the code and gave me the P0421 I don't know if anyone found the answer to this but im still looking for the right answer. Ive asked around and did my research and I heard i...
- HELP - P0421 on Mitsubishi Montero Sport 2001My Mitsubishi Montero sport has had the "service engine light" come on and off for a few years. Well, this time, it didn't pass inspection because the light won't go off. We just took it to the dealer and they said that P0421 was the code, and the B1 and B2 warm up cats aren't working. They want ...
- P0421,P0446,P0401 2003 hyundai santa fe 2.4 engine160k miles, car is sputtering on acceleration and cruising rough. Had a timing belt put on about a month ago and it ran fine, put new spark plugs in , but didn't help the way it runs. Any ideas?...
- 2003 Audi A6 P0421 DiagnosisCan somebody help me further diagnose? The car seems to run fine, but I'm a little uneasy to keep using it with the Check Engine light on.
The code is P0421.
My car is a 2003 Audi A6 Quattro 3.0...