I have recently had about $1620 worth of work done on my 2000 4Runner because the check engine light came on and the code was P0420.. My invoice says they replaced the exhaust pipe assembly. Now 2 weeks later the light is back on with the same code...are the 02 sensors part of the "exhaust pipe assembly" or are they now going to tell me I need a bunch (2-4) 02 sensors replaced.
View 3 Replies2002 4Runner 4x4, 180K miles. I bought this car about a year ago and don't know anything about its history before that but it seems to be in good shape.
About every month or two I take a trip that includes driving a few miles on a dirt road. It is a graded road in pretty decent shape. What has happened about 6 times during the year is that the CEL comes on while I am driving on the dirt road. The car continues to run well. When I get home and hook up my code reader the code is always P0420 Catalyst efficiency below threshold.
To save everyone the trouble of looking that up, this code indicates that either the upstream or downstream A/F Ratio sensor is bad. If both sensors test good then it is probably a bad cat.
What is different here is that after I clear the code, the CEL stays off as long as I stay on paved roads. So to summarize, I don't get the code every time I drive on a dirt road but every time the CEL has come on it is while I was on a dirt road.
So it seems that something about driving on a dirt road causes the CEL. Two obvious things you get on a dirt road are dust and vibration. What could be causing this? I did a visual inspection of the whole exhaust but did not see anything obvious such as cracks or leaks.
And of course I could live with this if I have to since it comes up under such limited circumstances. I just like to keep my cars running properly.
I have a 2003 Toyota Corolla, mileage app. 106,000. Check engine light first came on when driving to destination 40+ miles away (most of my driving is shorter, around-town trips). My mechanic said code is P0420 and so they reset it and said if it comes on again that I need a new cat converter. It did not come on until about 6 weeks later when I was on a longer trip again (had driven about 40-50 miles). Can you tell me if the P0420 code absolutely means that a new cat. conv. is needed or if it could possibly be a sensor or something else hopefully less costly than a new cc?
View 3 RepliesMK4 GTi - My check engine light came on a few days ago and when I checked it, it pulled code P0420.
Just this morning, the check engine light went away.
Is this a common issue? Or should I go get it checked just in case?
1989 toyota 4runner. O2 sensor is bad and has the check engine light on. No need to spend $100+ on the sensor. Is there a way to disable it so the light goes off?
View 19 RepliesI have a 2005 Toyota 4Runner. 355,000 miles. No problems with it until now. About 2 weeks ago Check Engine Light came on. I replaced spark plugs (they were due), checked coils and fuel injectors and still have Check Engine Light on with code P0301 (Cylinder #1 missfire).So compression tests were done and cylinder #1 had 120 psi and others 170. I suppose 120 isn't terribly bad but is significantly lower than 170.
Question 1: If I reset the check engine light (turn it off), do you think it will pass California smog test?
Question 2: What do I need to cure the problem? Engine rebuild? JDM? or retire the truck?
I bought an 04 elantra a few weeks ago. The check engine light is now on and I get code P0420 listed twice with my code reader. I have replaced the downstream O2 sensor and reset the codes only for them to return again. It is my understanding that this is going to be a convertor problem. My question is that from the research I have done it looks as though this car has two converters. One at the exhaust manifold and then another in the tailpipe. Which one is going to be the most likely causing my Check engine light to come on. Or do I need to replace both converters.
View 5 RepliesMy 2005 Dodge Dokota 4.7L V8 152,000 miles has an intermittent check engine light (CEL) code P0420 ('catalylst efficiency') that turns itself off.
1) 151,000 CEL on, code P0420, checked, cleared at dealer.
2) 151,948 CEL on, code P0420, checked, cleared at dealer (Cat Conv).
3) 152,200 CEL on, code P0420, checked, cleared at local auto parts store.
4) 152,597 CEL on. No checks.
5) 152,815 CEL turned off on its own
6) 152,849 CEL on. No checks.
7) 153,137 CEL turned off on its own.
Twice in this time CEL has came on soon after a fill up from near empty.
Engine runs fine, 18-19 mpg highway.
Have seen numerous on-line reports of other possible causes:
a) base engine problems (coolant or oil) -- coolant temp sensor
b) Air inleakage -- air systems or manifold
c) Lazy front O2 sensor
d) fuel pumps
e) timing or misfire
f) what else? - (gas cap, other...)
What to check first or categories to eliminate?
I was driving along today and my Check Engine light came on. I stopped at the nearest Advance Auto to have them pull the code and it came up with the P0420, Catalyst Efficiency Below Threshold (Bank 1). I asked what could cause this and they mentioned that the fuel that was put in could be causing it. They didn't mention any other possible causes. Any others? I'm thinking it could be the fuel because the last gas station that I stopped at and filled up at is one that I never go to, and maybe just got a bad batch of fuel.
View 14 RepliesSo today my CEL came on. I immediately looked at my mileage and I was EXACTLY at 500m past my oil change the other day. I checked the dip stick and lo and behold, it was about 3/4" past the full marker. I took it back to the oil change place and had them drain it down to a good level.
I had driven from NH to NY this week. I filled up my gas tank on my way home from NY. Gas cap was on nice and tight for sure.
The code is still on (not sure how many miles or drive cycles is required) for something to clear. I figured it was perhaps due to too much oil added. I decided a few hours later to take it to AutoZone and grab the diagnostic code. It's a P0420 code (Cat System efficiency below threshold: Air leak in exhaust before rear HO2S, AF Sensor Error, Fuel System Fault, Faulty Catalytic Converter).
My check engine light has been coming on and off and it seems to show P0420 for catalytic converter. The light stays off for about a week and it'll come on for a day or two and off again.
Wouldn't a failed converter stay failed? Can P0420 be triggered by loose/bad gas caps?
Had the check engine light in the 2005 F150 (90,000 miles) come on. Got the code checked and its P0420. I know that has to do with the cat threshold levels etc. so I believe I am looking to replace the o2 sensor, if I am not mistaken.
How hard of a job is this? Ive done a decent amount of engine work and worked in a shop in high school. Just looking to see if that is the right thing to try first, replacing the sensor, before replacing the cat.
Also I know its the right bank, but if I am not mistaken there is a before and after the cat o2 sensor, which do i replace? Both?
Some background. I have a 1998 Toyota 4Runner V6 2WD with about 150,000 miles. A few months ago the check engine light was flashing when I am travelling over 70mph. The dealership said nothing is wrong when I asked them to look into it. But I didn't get any codes from it. I read on-line that it could be a possible misfire so I changed the plugs and wires.
A few weeks ago, the check engine light came on and stayed on. I took it to a dealership to diagnosis the problem, they came up with Mass Air Flow sensor was shot. I replaced that, and reset the computer. It still comes on and flashes at highway speeds. I bought a low end computer to read the codes.
I got P300 (Random/Multiple Misfire), P302 (Cylinder 2 Misfire) and P305 (Cylinder 5 Misfire). Cylinder 5 has the coil-pack and Cylinder 2 has the wire coming off the coil-pack for Cylinder 5. So I replaced the coil-pack. The light is still coming on and flashing. How to stop the light from flashing. It comes on only when I am travelling past 70MPH. I have tried just rev'ing the engine up to the same RPM's as I am running when doing 70, but the light doesn't flash then.
I have a 2001 Honda Odyssey with 90000 miles. Lat last year around Oct/Nov time frame, check engine light came on. I took my vehicle to a local Auto Zone store and they scanned the code and told me it was P0420 - bad catalytic converter.
I replaced the cat converter with an after market model, however after 3/4 months (after driving 2000 to 3000 miles), check engine light came on with the same code. The mechanic changed the cat converter and put a new (after market model). Again after 3/4 months (2000 to 3000 miles) check engine light came on again. And this time the mechanic replaced the cat converter and also oxygen sensor. Now after 4 months or so the check engine light is on the vehicle again.
The mechanic is now saying that the problem is not with the cat converter and he is saying there is a lot of abnormal deposit on the vehicle. When he scanned again he found another issue that read something like "high voltage" and this time the guy thought may be due to short circuit (per code) the fuel injector is sending high volume of fuel and this is causing excessive fuel to go into the cylinder and hence high volume of emission. I replaced the fuse box again and after another 100 miles or, the problem is reappearing.
I have a 2001 toyota 4runner 6-cylinder 3.4L engine with about 197xxx miles on it. I just took it in for an oil change a few weeks ago and when they checked all the other fluids in the truck they said the coolant seems sludgy and dark. Also the check engine light and vsc trac and vsc off lights came on, a week or so before the oil change. I'm pretty mechanically inclined and do almost all my work myself with the limit of the tools i have, but i can't seem to figure out what is causing this.
View 6 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 Replies2001 Camry 4 cylinder. Check engine light came on yesterday. Advance Auto pulled out the code P0446 for the evap. emissions system vent circuit.
The car has no symptoms other than this and is current on all maintenance, but obviously it is a 10-year old car and so it goes.
About two weeks ago, while driving on a hot, humid summer night, the check engine light in my 1998 Toyota Corolla came on. The following day, I took it into my mechanic, who plugged it in and came up with the code P0441 (Purge flow fault). He told me it was likely related to the fuel vapor canister, though I see this can also have to do with vacuum lines for the purge valve and canister or a bad purge valve itself. My gas cap was, and had been, tight, so it wasn't something as simple as that.
Reluctant to deal with this immediately, I went back to driving it, and lo and behold - the light went off after several days! Unfortunately, the light came BACK ON after several more. And most recently (a few days after coming on again), the light has now gone off!
Both times the light has gone off, the weather has been rather wet, but otherwise, there doesn't seem to be a clear pattern. What this on again off again pattern might say about the problem?
I have a 2000 Toyota solara. Everything runs fine. No misfires or weir sounds. But the check engine light has been turning on and off. It turns off at random times and usually turns back on after I get gas. I finally got the code scanned. It is P1410. While at autozone I got a new gas cap based on prior postings and filled up the tank to see if that trick would work. To my delight, the cel turned off upon starting the engine. It remained off for thirty minutes before it came back on. So now I am stuck with the code.
View 4 RepliesMy 96 toyota celica check engine light is on and I get the code P0340. Also I can't seem to get my reverse light to work what could be the problem.
View 7 RepliesCheck engine light was on for some time when I had filler neck and cap replaced. Computer sensors did not re-set until 501 mile mark, when light came on again. Checking the web, I find that some who appear to have knowledge of problem say it could be hoses, sensors, valves, or evap canister--the charcoal canister.
Mechanic who did original smoke test and recommended replacement of filler tube wants to replace evap canister without checking anything else. What should I do? At wits end, and car needed to pass inspection 2 days ago. Car has 157,000 miles or so...