Code P0420

[Dylansdad]

Ok everyone, 2003 4 cyl. Camry LE, daily driver, threw this code coming home from a road trip, P0420

everything seems to be ok, got 30mpg on the short road trip, family of four loaded in

Any directions to look at ???

Thanks,

[Dylansdad]

I know this has nothing to do with making the car lower or anything else visible.........but 44 views and no help........??

[RickMN]

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

First try cleaning your MAF sensor. Buy a can of CRC MAF Sensor Spray cleaner.

Here's a link on how to do it. (Yours will look different) Clean MAF

Check for exhaust leaks.

Check for defective post-cat sensor

[TRD VVTi]

Originally Posted by Dylansdad

I know this has nothing to do with making the car lower or anything else visible.........but 44 views and no help........??

That's right. You had the code, you should have posted what it was for. I sure didn't feel like taking the time to look it up. You're the one with the problem, so it would help if YOU took SOME initiative.

It seems that you could have helped yourself out a little more in the time that it took to post that smart assed comment.

Cleaning the MAF won't do anything at all to help. It's either a faulty after cat sensor, wiring, or the convertor itself. It's pretty much impossible for an exhaust leak to cause that code either. Having a leak would kind of act like AIR injection and make the catalyst MORE efficient.

Check the online manual and follow the diagnostic procedure for that code.

EDIT:

Originally Posted by RickMN

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

First try cleaning your MAF sensor. Buy a can of CRC MAF Sensor Spray cleaner.

Here's a link on how to do it. (Yours will look different) Clean MAF

Check for exhaust leaks.

Check for defective post-cat sensor
__________________
I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: Rick's Blog

Last edited by RickMN : Today at 04:06 PM. Reason: new info

That information sucks.

I can't believe that you're really a "retired ASE Master/L-1 Technician! Why would you post inaccurate B.S. information like that?

[ghettosled]

it seems a little premature, but my money is on that you have a bad catalytic converter. you can try replacing that oxygen sensor since they arent too expensive, but i think youll have to bite the bullet and replace the cat.

[ShawnM]

9 times out of 10 its a weak or bad converter.
Calm down TRD, the info he gave is exactly what the dealer procedure usually is. As with any problem people post on here, we are all just guessing at it since we cant physically check out the car.

[TRD VVTi]

^ I'm calm.

If you have less than 80,000 miles on it bring it to the dealer.

If it's the convertor (likely problem/common) you are covered under the 8 year/80,000 mile Federal Emissions Warranty.

[RickMN]

If a cat is failing at 80,000 there's a reason for it. This poster may still have to replace his cat, but if he doesn't address the root cause of why it failed in the first place, it will just happen all over again with the new one. First off, TRD, this vehicle doesn't have an AIR pump. Even if it did, that inject air would only make the cat more efficient if the incoming exhaust was a lean misfire with too much unburned HC. If it was a lean mixture without excess HC (like an air leak), the AIR would actually drive the post cat sensor into a catatonic state--making it look dead.

Just so TRD can chill out a bit, cleaning the MAF and checking for leaks in the exhaust are the first two items to check according to both Alldata and Mitchell On Demand. I stand by my advice--clean your MAF and check for leaks—neither of which will cost you much of anything.

[TRD VVTi]

Originally Posted by RickMN

If a cat is failing at 80,000 there's a reason for it. This poster may still have to replace his cat, but if he doesn't address the root cause of why it failed in the first place, it will just happen all over again with the new one. First off, TRD, this vehicle doesn't have an AIR pump. Even if it did, that inject air would only make the cat more efficient if the incoming exhaust was a lean misfire with too much unburned HC. If it was a lean mixture without excess HC (like an air leak), the AIR would actually drive the post cat sensor into a catatonic state--making it look dead.

Just so TRD can chill out a bit, cleaning the MAF and checking for leaks in the exhaust are the first two items to check according to both Alldata and Mitchell On Demand. I stand by my advice--clean your MAF and check for leaks—neither of which will cost you much of anything.

It really doesn't matter if AllDate and Mitchell On Demand say to do it. It will not cause the code. Anyone that really does know what they're doing wouldn't go on a wild goose chase, or send someone else on one.

I know it doesn't have an AIR pump, I was making a comparison.

There is a reason the cat would fail at 80,000 miles...

...it's a common problem! Check into it yourself. I've replaced MANY convertors because they don't function properly. It seems making good convertors isn't one of Toyota's strong points. If there was another cause, I would think there would be other problems or codes stored in the system.

You should already know all these things. You know, because you're so heavily qualified and everything.

[toyo_tech02]

on 2003 4cyl camrys po420 is remedied by an ecu recalibration and updated covertor. there is a technical service bulliten addressing this. it should still be covered under emission warranty. take it to a dealer and they will take care of it for you at no charge if your car is within mileage.

[Dylansdad]

Hoorah! The light came on last Saturday on a road trip, turned itself off last night..........

Off the hook, for now at least, Thanks for all those who provided me some insight as to what may be the cause if it happens again, especially those who did not feel the need to be a smart a$$ about it

[TRD VVTi]

Originally Posted by Dylansdad

I know this has nothing to do with making the car lower or anything else visible.........but 44 views and no help........??

Here's a post from the first smart ass.

You're lights out only temporarily.

Dumb ass.

[Dylansdad]

Hey Jerk, it could have been a fluke, after some searching, having it reset to see if it was a fluke type of thing was the first thing mentioned to do. I didn't have to, b/c it did it all by itself.......end result the light is off.........

I know your parents must be so proud.......do you honestly get out of bed in that mood everyday?

[TRD VVTi]

Originally Posted by Dylansdad

Hey Jerk, it could have been a fluke, after some searching, having it reset to see if it was a fluke type of thing was the first thing mentioned to do. I didn't have to, b/c it did it all by itself.......end result the light is off.........

I know your parents must be so proud.......do you honestly get out of bed in that mood everyday?

Yep, I'm pretty monotone.

Are you lazy or just stupid everyday?

The online manual provides information to help out. Many times it's too overwhelming for people without automotive background. I actually enjoy helping people fix their vehicle. It isn't any fun when the person asking for help really isn't taking any intiative. You could have VERY EASILY posted what the code was for instead of expecting other people to look it up for you. It's in the online manual.

http://www.camrymanuals.com/index.ph...ction=celcodes

I didn't insult you with my post. I responded to you. I viewed your thread before there was a response. You didn't seem that concerned. Apparently you were concerned just enough to be a smartass regarding the views with no help. In the time it took you to rip on the people who viewed your thread you could have easily gotten some more information, like the link posted above from the online manual.

I felt compelled to reply when you were a smartass and the other guy was sending you on a wild goose chase. I addressed both of you.

I'm too blunt. Oh well. It's better than being like you.

I reviewed my response and stand behind it.

By the way, it wasn't a fluke. I will stand behind that as well.

Have a nice day.

[tjgeorge1]

My car: 2003 Camry, 4 cylinder 2AZ-FE engine w/California emissions (reside in PA - go figure), 98.5K miles.

Had a Check Engine Light (CEL) occur 3-4 days after an inspection that required a new gas cap (old cap would have failed inspection).

Brought it in to get it checked out for a diagnostic review, same out as code P0420...dealership said bad cat and quoted me $750-$800 to get it fixed that day since it would fail emissions (thank goodness I had passed emissions a few days prior). I told them I wanted to do some research b4 I committed to fixing.

Researched this and other online resources that suggested many others having same error code that went through replacing cat only to discover that did not address issue. I also read that cats should last much longer than my 98.5K miles suggested.

I read many instances that this P0420 code is a finicky readout that Toyota technicians do not have a great deal of success interpreting...many times it falsely indicates an issue where no issue can be found.

I reviewed some home based options to attempt & address CEL. For the 2003, I saw the EFI fuse removal for two minutes...did not work.

The one that worked for me was the removal of the negative battery post fitting...left off five minutes, came back and replaced. The CEL indicator went away and has stayed off for the 1st few days...only negative part of this is resetting clock and radio presets...big deal vs. close to $1K of cat repairs.