Subaru - Forester :: 2006 - Catalyst Efficiency Below Threshold Bank Code P0420
I have a 2006 Subaru Forester with 95,000 miles on it. Earlier today the CEL (solid) and cruise (flashing) came on while I was driving. I believe it may have occurred as I was accelerating up hill. I filled up yesterday, so I tightened the gas cap when I stopped. On my way home, I stopped by my mechanic and they read the code; P0420 Catalyst Efficiency Below Threshold Bank was the code that was read. They reset the code for me but told me that the catalytic converter is what needs to be replaced.
My question: Could the light coming on be incidental (i.e., is it possible that it was a "blip" and my catalytic converter is okay?)? My mechanic said he thinks it is, and that my car should last me quite a bit longer. I am asking because I've put in a bit of money into the car of late and I'm wondering if I should just jump ship. I should say that the majority of the repairs are maintenance (e.g., brakes, tires).
Prius (2004-09) :: CEL On / Code P0420 / Catalytic Converter Threshold Below Efficiency
I checked out a 2006 Prius yesterday a guy is selling. It had the CEL on (not sure why somebody would try and sell a car with that, but anyway). He said that it's because they get gas at a station that consistently doesn't tighten the gas cap enough but by the time the tank is down to 1-2 bars the light always goes away. Although I don't doubt his story, I absolutely doubted the cause. So I took it to get the code pulled and it was P0420, which is catalytic converter threshold below efficiency.
View 15 RepliesGolf IV / Jetta IV :: Error Code P0420 - Catalyst System Efficiency Below Threshold
On my 2002 (AVH) 2.0L 4cyl Jetta I have a persistent P0420 error code: "Catalyst System Efficiency Below Threshold"
I changed the oil, cleaned the Mass Airflow Sensor, replaced the coolant, thermostat, and coolant temperature sensor. But it's still showing up.
OBDII says it could still be:
A damaged or failed oxygen sensor (HO2S)
Downstream oxygen sensor (HO2S) wiring damaged or connected improperly
Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe
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
Ford - Explorer :: Check Engine Code P0420 - Catalyst System Efficiency Below Threshold
Book says "catalyst system efficiency below threshold (Bank 1)".. Is it just based on mileage or an actual bad O2 sensor or other bad system component?
View 14 RepliesAccent LC (2000-05) :: Code P0422 Keeps Popping Up - Main Catalyst Efficiency Below Threshold Bank 1
I have a 99 Tiburon 2.0 DOHC that I cant seem to get through emissions. The code, p0422 main catalyst efficiency below threshold bank 1 keeps popping up even after replacing the cat converter (twice) and replacing both 02 sensors. What else could be triggering this code and how to fix it?
View 2 RepliesHonda - Accord - Code :: P0420 - Catalyst System Below Efficiency / Bank 1
P0420 Catalyst System below efficiency -- bank 1
I've had this code for a couple months trying to trouble shoot it. My gas mileage has been affected, as I'm getting about 23/24 MPG city/highway. I replaced the upstream 02 sensor with am aftermarket Bosch variety( I'm not sure why a non-OEM one would make a difference, as long it's working correctly).
My car has 253k miles, the cat doesn't rattle and I don't smell any rotten eggs or anything, but it has to be clogged or the 02 sensor I got was defective. My engine runs fine and I don't have any problems accelerating or decelerating. It may still be the 02 sensor since the gas mileage decrease is so significant, or it could be my converter is really clogged up.
Ford Escape / Hybrid :: 2002 V6 - CEL Code P0420 For Low Cat Efficiency Bank 1
I have been getting a CEL P0420 for low cat efficiency bank 1 on my 2002 Ford Escape V6. The truck runs fine otherwise. I have ran two loads of Cataclean and the light keeps coming back a few days after CEL reset so I am pretty sure one of cats is done. I am going to replace with an aftermarket cat. My question is, with this code, do I need to replace the front exhaust manifold cat or the rear manifold cat?
View 1 RepliesPrius (Gen 2) :: Engine Misfiring - Catalyst System Efficiency Below Threshold Bank 1
I've got a 2004 Prius with about 140,000 miles. Overall, the car has worked great, and I've kept up with regular service.
Several months ago, I started having bad misfiring of the engine. When I got it into the shop, it turned out to be two faulty ignition coils. The shop advised me to replace them all, which I did. Soon afterwards, however, the CEL came on, indicating a P0420 - "Catalyst System Efficiency Below Threshold Bank 1".
Lexus RX 2004-09 :: RX330 - P0430 Catalyst System Efficiency Below Threshold (Bank 2)
CEL and VSC came on so i ran the diagnostic tool and got this msg :
P0430 Catalyst System Efficiency Below Threshold (Bank #2)
what could it be? The car performs fine, no MPG decrease, no performance impact..
Lexus GS 2006-11 :: GS450h - P0430 Catalyst System Efficiency Below Threshold Bank 2
Have the EML on on my GS450h, read the fault codes and I have 2 fault codes that are identical (P0430). I cleared the fault codes and it stays off for a day, then as soon as I go above 60mph the next day, it comes back on again, the faults are stored and not current codes. I've not noticed any MPG loss or loss of power whatsoever! So am I safe to assume its not the catalysts? Only other thing I could think of is an o2 sensor gone bad perhaps? I don't want to spend money really as I'm about to sell the car for a more economical one for my 150miles per day commute to work! Just had all 4 wheels refurbished too which set me back a fair amount, now this!
View 2 RepliesFord F-150 (2004-2008) :: P0420 Catalyst Below Threshold Bank 1
2004 F150 5.4L V8 ...
P0420 Catalyst below threshold bank ...
O2 Sensors or Catalytic Converter ...
Maintenance / Repairs :: Code PO430 / Catalyst Efficiency Below Threshold
I was app. 10 miles from home & engine started missing & went into limp mode & yes the light flashed . I limped it home anyway & now have a PO430 code . # 2 spark plug died & caused this , danged plug didn't have a hundred miles on it since new . Replaced that plug & everything's fine except that code . Vehicle runs great . I've also read an 02 sensor could cause this code .
View 4 RepliesGolf IV / Jetta IV :: 1999 / 2.0 - Code P0422 Main Catalyst Efficiency Below Threshold
Has around 173,000 miles, with a fresh cat installed a couple hundred miles ago. I was getting this code before, that is why I had a new cat installed. The code finally came back, and just recently I had to replace the crankshaft position sensor. After the sensor change, it was running great. The CEL came back on during a rainy day, I cleared it and was good for a few days. Then it rained again, and it came back. I couldn't afford a new OEM cat, I grabbed the best rated one I could from Amazon and had a shop install it. I know non OEM can be an issue, but I hope it is just an O2 sensor going bad.
View 2 RepliesPassat (B5) :: Code P0421 - Warm Up Catalytic Converter Efficiency Below Threshold (bank1)
So the code reads "warm up catalytic converter efficiency below threshold (bank1)" ?? What it could be?
View 12 RepliesToyota - Camry :: Check Engine Light Code - Catalyst System Efficiency Below Threshold
My 1999 Camry with 169700 miles has this 'check engine light' code: "Catalyst system efficiency below threshold". We have a mechanic we trust so we'll bring it to him this week. We spent a couple thousand fixing this car about two years ago and I'm not sure it is worth doing that again. Carmax offered us 1200 for it around this time 2012.
View 17 RepliesFord - Ranger :: 1999 - Check Engine Light / Catalyst Efficiency Below Threshold Fault Code
99 Ford Ranger 4-cyl. Check engine light is on; pulled fault code: "catalyst efficiency below threshold, bank 1." Cat converter is new as is rest of exhaust, o2 sensors are new, and its been recently tuned up.
View 6 RepliesElantra XD (2001-06) :: P0420 Code - Catalyst Efficiency Below Normal
P0420 code. Catalyst Efficiency Below Normal (Bank 1)
This was the explanation I got from autozone. First question is how serious is this? The car seems to drive fine and normal, but I just purchased this car about a month ago. The light turned off after the guy at autozone plugged in the scanner. I am sure it will come back on again after some driving. Is it ok to drive with it on?
Santa FE SM (2001-06) :: Code P0430 - Bank 2 Cat Efficiency Low
05 santa fe/3.5L/ owned since new. Had a misfire problem and solved that by changing coils/plugs/wires...
Still getting a P0430 code (bank 2 cat efficiency low)
Following the Repair manual troubleshooting of that code says
Read H02S - got a scan tool and did that -
Comparing Bank 1 H02S1 and 2 show they are are different voltages and do not follow.
Comparing Bank 2 H02S1 and 2 show nearly identical traces.
I also checked the wiring harness around the sensors and check for air leaks...couldn't hear/see/feel any.
My conclusion based on the info obtained is that the bank 2 cat is bad and needs to be replaced.
Golf IV / Jetta IV :: 2001 - Intermittent P0420 Cat Below Efficiency Code Appears
2001 Jetta 2.0, manual trans
I've been having problems with intermittent P0420 cat below efficiency code. Everything else is fine, no codes, runs great. I tried spacing the post cat sensor back w/ extender bung (after replacing post cat sensor..) and still get the code. I don't hear any rattling or anything to make me think cat is bad physically. I was told by dealer that a code update might resolve for $200 - which got me thinking that that if that was so, it should should be a problem which Feds should be aware.
I searched safercar.gov and found this NHTSA ID Number: 10054864
It's a service bulletin saying that VW made the limits too sensitive and it seems there was a customer satisfaction campaign to update code - pdf on site CSC-10054864-8736
It says:
May 2007
Subject: Emissions Service Action N7
1999-2002 Jetta, Golf and GTI with VR6 Engine
Update Electronic Control Module (ECM) Software for Catalytic Converter Monitoring System Dear Volkswagen Owner: We are writing to inform you of an emissions service action on some 1999-2002 Jetta, Golf and GTI VR6 engine vehicles. Our records show that you are the owner of one of these vehicles.
What Is The Problem? The electronic control module (ECM) software for the catalytic converter monitoring system is too sensitive. This can cause the MIL to come on, and some vehicles may exceed Federal and/or California emissions standards. Also, in some cases this leads to unnecessary catalytic converter replacement. What Will Volkswagen Do? Dealers will update the ECM software.