Toyota P0420 P0430 - Toyota Highlander Cat Efficiency Codes


You greetings and welcome back to the car doctor studios in Anchorage Alaska. Thanks for stopping by got a quick tip today for owners of certain Toyota, products experiencing a code p, 0 for 2, 0 and/or code. P, 0 for 3 0 a catalytic converter efficiency code.

And this coverage should include your models 2002 through 2006. It should cover the highlander and the Camry, the Solar and the rav4 with the 2 for variable valve timing engine. So basically there is a technical service bulletin on this rig and. They were extending the warranty coverage for like eight years and 80,000 miles, but all the vehicles affected under this tip are going to be outside a warranty or emissions warranty on it. So you're going to have to suck it up on the repairs, but I think I can save you a few bucks.

And basically with any cap efficiency code like this it's handy, if you do have access to a scan tool, and you can watch the o2 sensors. And the o2 sensor operation should show you whether you indeed, have a cat. Problem or maybe an o2 problem on the outside edge, but it's just not common with this code on this particular vehicle it's, a highly probable that you're going to need to replace the cat. We've seen them fail at eighty-nine thousand miles. This particular rig is a 150 K. It's got the original cat, and it's never been replaced along with the original.

Oh, 2's also the technical service bulletins. In this case is going to refer to an update, which is a PCM reprogram that changes the parameters of the cat. Efficiency testing and also the catalytic converter is an updated style cat. So basically, when you're confirmed these the probability of a cat being the cause we're, looking at all 402s and basically the front Oh, two's, Bank, one and bank two are should be fluctuating between rich and lean basically between zero and one volt. And then the rear o2 activity should be a lot less. And if you pull them up on graphene on the scan tool, you should be able to notice the difference. However, if the rear, oh twos.

Are about as active as the front that's showing that the catalyst is not actually catalyzing burning up oxygen in the process, and therefore the're going to be switching about the same rate as the front, oh twos, which is going to indicate that the cats are bad there's, an outside chance that you may have a no2 going bad. In this case, it's probably referred to as an air fuel ratio sensor, not an o2 on the upstream side. So anyway, in this case, I've determined that the cat itself is bad. I did give.

The customer an option to replace all 402 s at the same time, but though 2's are pretty expensive that was going to add another $700 to the bill. In this case to do the front air fuel ratio sensors and the downstream, Oh twos. So we're just going to wing it and pull the old O twos out of the cat and install them in the replacement cat.

So basically, in this case, what I have done is I, raise the vehicle. And then remove the two lower exhaust pipe, flange bolts, the bolts with the springs on them. And then.There are two brackets that you'll need to remove on either side of the lower end of the header pipe, where the cap flanges connect to the exhaust pipe, there's, two brackets that connect the bottom side of the cat to the block face little angle brackets, and you want to remove the nuts and bolts and those two brackets as well. And then you can lower the vehicle down.

And what you want to do first is remove the engine cover, and then remove your heat shrouds on the front and top face of the cat assembly. That allow you access to remove the bolts that secure the cat manifold assembly to the cylinder head. So once you've done that, go ahead and remove all 402 sensor wire connectors. You can follow them up on the right and left side of the engine around the ends of the valve cover there's, two sets of connectors. You want to just disconnect your connectors and then remove your manifold assembly. So once you've removed it I, threw mine up in a bench vise here, and I'm, just removing the o2 sensors that way. I'm loosening them.

So that I can transfer them later and put them in the exact same position. You certainly wouldn't want to get the positions messed up at this point, the connectors won't, the connectors won't reach. And if they did, you'd have all sorts of trouble with your you DEP, check engine, lights and whatnot afterwards. So anyway, basically just reversing the installation procedure.

Do you get things button back up I'm going to start a backup and monitor my Oh two sensors? And as you can see here. I've got them graphed out, and the Fronts are switching normally. And the rears obviously are not switching at the same rate, they're staying pretty constant.

So that shows us that the cats are functioning. Normally then I just go ahead and clear the codes and confirm the repairs, and this thing's going to be back on the road. So once again, I, thank you for stopping by the car. Doctor studios, I hope, this helps, and I wish you good luck with your repairs have a good one.

Dated : 07-Apr-2022

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