It says warm up catalyst below threshold (bank 2). Is this just an o2? and is it upstream or downstream if it is? When I scan other cars at work it normally says system is too lean/rich for o2's.
View 2 RepliesI just bought a 2002 2.8L Passat 4Motion. On the way home, the check engine light came on. My friend lent me his generic brand diag tool to scan that check engine light. It came up with two codes. The first one was:
P0421
Warm Up Catalyst Efficiency Below Threshold (Bank 1)
The second code was:
P0431
Warm Up Catalyst Efficiency Below Threshold (Bank 2)
What this means or what I need to do to fix it? Is it a matter of cleaning something or replacing something? If it's something I can figure out, I'll do it on my own. Mistakenly, I erased the code and now the light is gone--thought I was deleting the code from the handheld unit. I can't open my hood.
2004 F150 5.4L V8 ...
P0420 Catalyst below threshold bank ...
O2 Sensors or Catalytic Converter ...
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".
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..
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 RepliesI 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).
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 RepliesI have a 2002 GLX Wagon 2.8 30v, and was getting Cat warm up threshold low code, on the driver side due to the cat being bad. As a temp fix I decided to use spark plug haulers to gap the sensor. When I removed the O2 sensor I wiped the dirt off with a paper towel, which was clean and dry. I put the sensor back on, but now I am getting 4 codes which won't go away. p0036 p0056 p0141 p0161. These are O2 heater circuit codes both bank 1 and 2. I did not touch bank 2 so I don't know how I could have caused this error. I tried to take off bank 2 sensor but it is really stuck on there.
View 3 RepliesI 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 RepliesHas 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 RepliesOn 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
So the code reads "warm up catalytic converter efficiency below threshold (bank1)" ?? What it could be?
View 12 RepliesMy 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 RepliesBook 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 Replies99 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 RepliesRecently I pulled code P0420, AKA Bank 1: Efficiency Below Threshold.
To start from the beginning...several weeks ago my EPC light came on so, like most educated consumers I decided to buy a vag-com. I pulled the codes and got both the Bank 1 and Bank 2 efficiency below threshold codes (p0420, p0430). I reset the light and literally within 3 minutes the EPC light came back on only this time just Bank 1.
So I drove around again for a week and the check engine light came on this time, back to Bank 1 and Bank 2. Whether trying to replace the spark plugs will possibly fix the misfires, its Cat Converter replacement or possibly just replacement of 02 sensors. I have been reading mixed responses.
FYI I use synthetic oil and chance the oil every 7500-9000 miles, have 89,000 miles and have never changed my spark plugs.
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.
I have a 2006 F-150 with the 5.4L. I got the check engine light and the computer says catalyst deficiency bank 2. So I assume the passenger side converter is blocked. Is there anyway to either take out the cat and replace with a piece of straight pipe and bypass the o2 sensors or take the cat out of the housing and put the housing in and then bypass the o2 sensors.
View 14 RepliesI just bought a 2000 VW passat with 63k. I had it for a week and check engine light came on. 30 v engine ....
p0431 /16815 bank 1 below threshold??
p0421/16805 bank 2 below threshold??
Cat? or 02 sensors???
2003 passat wagon 2.8l v6 with p0421 and p0431...a slight miss as well...
Cold start up is fine and initial driving. After car warms, there is a slight shutter at idle (just occasionally) and upon acceleration with low rpms. (It really feels like a miss) Went to AutoZone and came back with the codes above. I thought it might need a new coil but now I am not really sure. I want my performance back but seriously doubt cats are bad at the same time.