5th & 6th Generation (2002-2006 & 2007-2011)Toyota Camry Discussion for years: 2002-2006 & 2007-2011
Topics of discussion range from fuel economy, safety, modifications, performance all involving America's favorite family car, the Toyota Camry.
5 months ago i replaced the O2 sensor on the upper part. Now getting a reading that the Catalytic is not performing right. Is there another sensor that could be bad or the one i replaced is bad? If so, Ill go that route. OR is there a way to clean out the CAT? Iv read a few forums on this. But want to make sure that im getting the correct info!
5 months ago i replaced the O2 sensor on the upper part. Now getting a reading that the Catalytic is not performing right. Is there another sensor that could be bad or the one i replaced is bad? If so, Ill go that route. OR is there a way to clean out the CAT? Iv read a few forums on this. But want to make sure that im getting the correct info!
What kind of miles? What brand of sensor did you install? Did the car have other symptoms prior to the initial sensor replacement? Any sign of exhaust leakage, like at the flex pipe?
Modern cars have a A/F sensor upstream of the cat and a sensor downstream of the cat that infers the catalyst effectiveness by measuring the difference in O2 levels between the first and the second sensors. If the upstream sensor isn't 'quite right', it's possible for the ECU to set the converter effectiveness error code. The same would apply if the exhaust has a leak that allows it to 'suck up' some air.
Of course, with high miles or contaminants (e.g. oil consumption), it's possible that the converter is ineffective. But proper diagnosis is needed, or you'll be out of $$$ and still have the problem.
What kind of miles? What brand of sensor did you install? Did the car have other symptoms prior to the initial sensor replacement? Any sign of exhaust leakage, like at the flex pipe?
Modern cars have a A/F sensor upstream of the cat and a sensor downstream of the cat that infers the catalyst effectiveness by measuring the difference in O2 levels between the first and the second sensors. If the upstream sensor isn't 'quite right', it's possible for the ECU to set the converter effectiveness error code. The same would apply if the exhaust has a leak that allows it to 'suck up' some air.
Of course, with high miles or contaminants (e.g. oil consumption), it's possible that the converter is ineffective. But proper diagnosis is needed, or you'll be out of $$$ and still have the problem.
Clock reads 160k, Used Bosch sensor, No exhaust leaks found, Only symptom prior was Gas mileage dropped but fine after replacement of O2. As far as Oil goes, there are no leaks. But it does seem to go through at least a quart between oil changes (every 3k-4k miles)
Do you have a CEL code? If you do, post up the code.
My car is a V6 and it has 4 sensor. One in front by the front cat, one in
back by the rear cat, two under after both cat. So with out a code, we won't know which sensor is bad.
The code it shows is "P0420".
This car is a 4Cyl.
After looking up new O2 sensors. The only option for a denso downstream is a "with California emissions". (vs federal emissions) Does this make a difference?
Was the front cat for me at 140k (02 XLE 2AZ-FE 4cyl). Likely your problem also. Leaking valve seals and foolishly "seafoaming" helped it along. There was a TSB to replace the front cats up to 80k. That replacement included a upgraded cat media, and an ECU reprogram.
Some things to know from personal experience.... Factory Denso o2 sensors usually foul before they actually fail. You can try cleaning the DOWNSTREAM (where the reading and CEL code is set from) o2 sensor with throttle body cleaner followed by MAF cleaner. If there is hard carbon inside the tube holes that won't clean, try soaking in gas, or replace it. Replacement o2 sensors should be Denso only. Do not use universal, or any other type than Denso. For the cat, it should also be factory only. The short answer why is the ECU is expecting specific readings with a high efficiency threshold. Throw on a aftermarket cat with different media, or a generic o2 sensor that may send a different reading, you will likely see the light again sooner than later.
The code it shows is "P0420".
This car is a 4Cyl.
After looking up new O2 sensors. The only option for a denso downstream is a "with California emissions". (vs federal emissions) Does this make a difference?
Sorry for late reply, Holiday came up.
Yes, the correct emissions spec makes a difference. You have to have a sensor with the right spec or 'emissions family'.
Take a look at http://www.obd-codes.com/p0420 - the link gives you the items that can cause the issue. On OBD2 cars, you can monitor the O2 sensor waveform with a relatively cheap (<$100-150) scanner - look at the one at Harbor Freight for $130; Amazon also has them, or you can get some that let you monitor stuff on a smartphone or a laptop. Search "OBDII scanners". Looking at the front sensor waveform and the rear sensor response will help you isolate the problem - if the 2 are the same, the catalyst is a likely suspect. If you simply have too-high O2 readings from downstream sensor, I'd look for excess air getting in the exhaust.
Yes, the correct emissions spec makes a difference. You have to have a sensor with the right spec or 'emissions family'.
Take a look at http://www.obd-codes.com/p0420 - the link gives you the items that can cause the issue. On OBD2 cars, you can monitor the O2 sensor waveform with a relatively cheap (<$100-150) scanner - look at the one at Harbor Freight for $130; Amazon also has them, or you can get some that let you monitor stuff on a smartphone or a laptop. Search "OBDII scanners". Looking at the front sensor waveform and the rear sensor response will help you isolate the problem - if the 2 are the same, the catalyst is a likely suspect. If you simply have too-high O2 readings from downstream sensor, I'd look for excess air getting in the exhaust.
Well over the weekend I had to do oil changes on all vehicles so I unhooked the battery cable on the car to see if it would get rid of the code. Well it did and has not came back on. Maybe it was a fluke this happened .I have a Actron CP9575. And if the code comes back I guess I put this on it and take a look.
Well over the weekend I had to do oil changes on all vehicles so I unhooked the battery cable on the car to see if it would get rid of the code. Well it did and has not came back on. Maybe it was a fluke this happened .I have a Actron CP9575. And if the code comes back I guess I put this on it and take a look.
Been there. Did that for 2 years getting through inspections. Always came back eventually. Takes about 60 miles to recalibrate. If your going to see it again will be after being on the highway for a while. soon as you exit highway, poof there it is...Mass State emissions has caught on to that trick. They no longer rely on tailpipe emissions, they check the codes. And for 60 miles after removing the battery terminal the emissions status code is "not ready". They saw that, said ahahaaaa...left me with a scarlet "R" (rejected) sticker on my window.
Last edited by leakyseals; 11-29-2011 at 07:38 AM.
Just giving an update, Car has drove for 250+ miles and no light yet. And I also found the upsteam sensor i replaced. It is a Bosch P# 15733. As of now Im just waiting to see if and when it comes back on. Being its my wife's car and she drives like everyday is Sunday. I took it out for a spin after I reset the code and drove it like i stole it. One might think this car was a diesel upon first floor stomp. did this 3 or 4 times and it all went away. (smoke that is)
Just giving an update, Car has drove for 250+ miles and no light yet. And I also found the upsteam sensor i replaced. It is a Bosch P# 15733. As of now Im just waiting to see if and when it comes back on. Being its my wife's car and she drives like everyday is Sunday. I took it out for a spin after I reset the code and drove it like i stole it. One might think this car was a diesel upon first floor stomp. did this 3 or 4 times and it all went away. (smoke that is)
What exactly was the sequence to know what worked. Did you disconnect the battery and replace the upstream o2 at the same time, or separate? Also did you notice a change in the smoothness of the idle?
About six months ago it threw a code for the upstream and I replaced it (with the bosch 15733) at the time i did not have a scanner and was told this by parts store. I dont think i ever unhooked the battery when i did this.
I still haven't done anything yet for the code this time but unhook the battery. Last post may have been confusing.
Now that you mention it at times the car idles really low almost to the point you think it may die.
About six months ago it threw a code for the upstream and I replaced it (with the bosch 15733) at the time i did not have a scanner and was told this by parts store. I dont think i ever unhooked the battery when i did this.
I still haven't done anything yet for the code this time but unhook the battery. Last post may have been confusing.
Now that you mention it at times the car idles really low almost to the point you think it may die.
Ok, when the replacement of the upstream o2 was done the CEL code was unknown, you trusted parts dealer. Now your getting a P0420, performed a battery disconnect CEL clear.
What I think...It will be back eventually. Your on the edge of catalyst efficiency according to the ecm settings. Because of today's strict pollution standards, the CEL efficiency occurs at 90+% (meaning its got another 50-100k before it clogs). The catalyst efficiency code comes from the downstream sensor, the one that wasn't replaced.
Sometimes when the CEL po420 occurs, parts dealers will sell you an o2, or maybe it really was the bad upstream o2 code. If it was the upstream sensor that failed would have expected a BETTER idle, because the upstream sensor has a dual role (air fuel trim and o2 sensor). for that reason, Denso OE is always recommended. Now you have 2 different types of sensors upstream and downstream reporting to the ecm.
Am I suggesting getting rid of the bosch o2? No, not yet. Do I think replacing the o2's and disconnecting the battery will make the p0420 go away permanently? Unlikely.
There is a TSB for a replacement cat and a ecm reprogram for 02-04 I4 Camrys up to 80k. Basically an admission that the factory program, and the cat used don't last. 2002 Camry catalytic converter
You made it this far, so the cars running pretty good. Going on the highway for a while, getting hot then exiting the highway can many times trip the code. If the code comes on very infrequently and you can get through inspection, keep going till you can't keep the light out. Should be another couple years. Then have the front cat/manifold replaced, again use the factory upgraded cat only. Can be had online for about $400. Then go to the dealer and request the latest flash, kind of like your computer does every so often
The driving style contributes as well. Not getting that cat hot enough on a continual basis causes the cat media to load up until it can no longer function correctly. The furnace goes out, so to speak.
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