PO402 Cat efficiency code?? - Toyota Nation Forum : Toyota Car and Truck Forums

Panhead Jim · 02-11-2011, 08:38 AM

2002 Camry 4 cyl. Clear the codes, drive the car 6 or 8 drive cycles, then the light comes back and throws the code PO402. Computer says this is cat efficiency issue. If anybody has a list of the possible culprits for this code, I sure would appreciate it. BTW - 2 cans Seafoam in full tank of fuel yesterday. I read somewhere that somebody had had success with it on PO402 in 4th Gen. Prolly EGR code for 4th Gen, though...
Thank you bunches.
Jim

**TOYOPARTSMAN** · 02-11-2011, 09:53 AM

I tried looking that up for you, but in the FSM I only come up with that code on the 6 cyl, not the 4.

Panhead Jim · 02-11-2011, 10:43 AM

Quote:

Originally Posted by TOYOPARTSMAN

I tried looking that up for you, but in the FSM I only come up with that code on the 6 cyl, not the 4.

Do you mean the cat efficiency definition by the computer or the PO402 in general? My concern with the light coming on - staying on is that until I can resolve, I run the risk of not knowing when some other "checkengine" issue arises. Thank you for your help!
Jim

**TOYOPARTSMAN** · 02-11-2011, 11:20 AM

The P0402.

When I was looking up that code, all the information pertaining to the P0402 code was for a 6 cyl.

Quote:

Originally Posted by Panhead Jim

Do you mean the cat efficiency definition by the computer or the PO402 in general? My concern with the light coming on - staying on is that until I can resolve, I run the risk of not knowing when some other "checkengine" issue arises. Thank you for your help!
Jim

profuse007 · 02-11-2011, 11:23 AM

The only cat system efficiency system below threshold is P0420 (not P0402). I have had it on my 4runner goes on once awhile but it turns off. I have experienced with it for over a year now.

**TOYOPARTSMAN** · 02-11-2011, 11:52 AM

If it is a P0420, I do have information on that.

profuse007 · 02-11-2011, 02:14 PM

Please list the information.

**TOYOPARTSMAN** · 02-11-2011, 02:32 PM

Did you need information on your 4Runner?

Quote:

Originally Posted by profuse007

Please list the information.

Agent556 · 02-11-2011, 06:25 PM

http://www.dtcsearch.com/P0402/

http://www.dtcsearch.com/P0420/

***JohnGD*** · 02-11-2011, 08:07 PM

Is the engine well tuned? How are the spark plugs? Valve clearances/stem seals may need to be checked/replaced?

If new sensors don't fix this problem then it's the catalytic converter, especially if you confirm it with a smog check.

Under an old TSB some covered vehicles had ECM reprogrammed and a new catalytic converter installed.

Quote:

Originally Posted by Panhead Jim

2002 Camry 4 cyl. Clear the codes, drive the car 6 or 8 drive cycles, then the light comes back and throws the code PO402. Computer says this is cat efficiency issue. If anybody has a list of the possible culprits for this code, I sure would appreciate it. BTW - 2 cans Seafoam in full tank of fuel yesterday. I read somewhere that somebody had had success with it on PO402 in 4th Gen. Prolly EGR code for 4th Gen, though...
Thank you bunches.
Jim

profuse007 · 02-11-2011, 08:16 PM

no for the op. I have techstream

somick · 02-15-2011, 11:25 AM

That what I found in my archives. I hope it will help you:

P0420

TSB No. EG013-04

Quote: “Some 2002 - 2004 model year Camry vehicles equipped with the 4 cylinder (2AZ-FE) engine may exhibit a M.l.L. ON" condition with Diagnostic Trouble Code (DTC) P0420 (Catalyst System Efficiency Below Threshold, Bank 1) in the Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM). The ECM (PCM) logic has been modified and a redesigned catalyst has been provided.
NOTE :The repair procedure in this TSB is similar to TSB No. EG013-04 "Excessive Sulfur Dioxide Odor." The recalibration of the ECM (PCM) should only be performed ONCE.”

Good luck,

Sam

NegativeTen · 02-15-2011, 12:50 PM

By and large the P0402 code can be a number of things related to the emissions system (and a few things completely unrelated). I'd first check all your vacuum lines and make sure you have no cracks or rotted connections. Make sure the seal around your gas cap is in good shape (though it often throws a P0400 I think, or P0402, I can't recall). Being that it's bank 1, that means the issue is in front of your catalytic converter (the O2 sensor in bank 1 is giving an unexpected reading).

Beyond those things, a faulty or clogged EGR valve (or purge sensor/solenoid) is most likely the cause. You can often take the EGR Valve off and give it a thorough cleaning (with chlorinated carb/brake cleaner and a wire brush), add a new gasket and you should be set. If the issue is the purge solenoid, I don't know of any way to remedy it, beyond replacing it.

Just as an aside, on some domestic vehicles (GM products in particular), I've seen the coolant temp sensor (SU108, most commonly) be the cause of a number of emission DTCs. I can't explain why, but they happen. On Toyota, though, I'm not entirely sure. Verify that your temperature gauge is reading accurately and radiator fans are kicking on to rule it out, though.

This isn't specific to your particular vehicle (though, being an 02 makes it even more likely), but in my experience that's often been the cause across the board of different makes and models.