Camry Check Engine Light Went Out

Car: Toyota Camry 2002
Mileage: 150K

Check Engine light went on a few days ago.

Checked codes and got these (3):

  1. P0420
  2. P1310
  3. P0420 P (“Pending” ?)

I also checked I/M Readiness and got these suspicious-looking values:

NOTE all the other I/M values were N/A

Researching the Codes, it sounded like Ignition, and possibly the O2 sensor on the Catalytic Convertor. I had just had some engine work done by the dealer – actually, replaced spark plugs – so I figured to go back and bitch him out for screwing up my car.

A few days later, before I could engage my Rage, I went back and re-scanned. First I noticed the CEL was now OFF. Scanning, I now I get “NO CODES”, and all the I/M values are now N/A; No more “NOT RDY”.

What do you all make of this?
Should I be concerned now that the CEL is Off, and I get No Codes with a scan?
Or maybe I should take it to AutoZone for their free CEL diagnosis – would their machine be more thorough than mine (Autel MaxioScan 300)??

Would appreciate any suggestions.

First of all…the CEL going off is a good thing…a very good thing. If you are concerned then let a couple of different auto parts stores scan your vehicle just to be on the safe side. I’ve never heard of an Autel MaxioScan 300 so I have no idea how good or bad they are.

Update: I just checked out the Autel Maxioscan 300. At $21…I’m surprised the thing even turns off and on much less reads vehicle codes.

Unless a car is running poorly or showing any change in how it runs, the first thing to do with codes is to note them, but just clear them to see if they come back.

It would also be odd to go yelling at the dealer who did the recent work. Just because they did some and the light came on soon after, that doesn’t mean the two things are related. You could simply take the car back to them if you have good reason to suspect a connection, and not “bitch” or “Rage” but see what they have to say about it. You didn’t say what kind of work was done other than spark plugs so it’s hard to say. But you can’t trigger those codes by replacing spark plugs


Here’s some reading material

The dealer’s scan tool is far more capable than yours. It can read data yours can’t even dream of, and it can perform tons of bi-directional tests

Yelling at the repair shop, especially when it’s 99% likely not their fault is not a good thing. The 1300 codes are an igniter circuit. The p 0420 means your cat converter is not working as efficiently as the ECM. Thinks it should. A very common problem on the 2az motor is that the tabs for the ignition coil connectors break as soon as you breathe on them. Bad plastic. Nothing anyone could do to prevent it. When it happens to me, I put a dab of rtv to prevent the connector from moving off the coil. Yes, you could have a new connector with leads soldered on, but in time, with heat, it’ll happen again. NOT saying that’s what it is for sure, but I’m a Toyota master tech and I see it all. As far as the converter, it’s the one in the manifold. Don’t let anyone else tell you it’s the secondary one in the mid pipe. It happens. It wears out. Kindness will always get you farther than rage. But, I agree with the above posts. Clear them, drive the car, and see if they come back. It’s in almost every flow chart for dtc s in toyotas repair manual. Good luck.