[newgrowthcontracting]

Help please, The code comes on and goes off on it own. It will stay off for a tank of gas then comeback for awhile. I have a Innova 5510 scanner and have graft both bank 1 and bank 2 02 sensors. I don't know what to make of data but maybe someone can help. I have ordered both bank 1 02 sensors by Denso. When I replace the sensors plan on running a borescope in through the 02 sensor ports and looking at the converter. We do not have emissions but I hate seeing a check engine light on.

 

[Sienile]

Check for an exhaust leak at the rear cat where it goes into the crossover, but it looks like the cat may have burnt through by the graph.

 

[newgrowthcontracting]

Check for an exhaust leak at the rear cat where it goes into the crossover, but it looks like the cat may have burnt through by the graph.

So a exhaust leak past the bank1S2 will sill cause issues? If I had a vacuum leak or injector issues I would see it in the fuel trim? The van is a 2011 TC with 118,000. I changed coils, injectors and plugs about 10,000 miles ago. I did so because I had a coil pack fail on cylinder 3. If anyone remembers in a old post I had the left cylinder head replaced due bad valve seats causing a misfire on cylinder 2. The P0420 started showing up 2 days after the head replacement. I put this aside because I had quality issues with the repair I received form the dealership. They charged me full labor even though they did the short cut and my TC cover and right valve cover were leaking oil. They agreed after 6 months to fix the oil leaks if I paid for parts since I paid the labor already and should have been done when the cylinder head was replaced. I did not trust them and put a camera under the hood and found their mechanic doing a bad job. He did a 11 hour job in 3 hours and leaked worse than when I took it to them. I had to meet with the general manager about this who had them redo the repairs for the third time. Now I'm back to the P0420 they say has nothing to do with repair.
I took it to another shop who says it's just a hiccup right now and I would be throwing parts at it. To wait until it becomes more frequent and can tell what's going on.
If I had a vacuum leak around a fuel injector could it cause this? Can I spray some carb cleaner around them to see if it changed the idle?

 

[Sienile]

I don't think a vacuum leak could cause this. The downstream sensor is the one with the erratic reading that is triggering the code. There's really only 3 things it could be: the downstream sensor, an air leak near it, or a bad cat. When you had the bad coil on #3 the injector would have been firing and putting excess fuel into the cat, which could have ruined it or passed through and contaminated the sensor. It definitely would have gotten extra hot while that was going on.

 

[newgrowthcontracting]

Right, I had no choice but to keep driving. We were in the Blueridge mountains and the closest parts store was 20miles. We were towing our pop up trailer and It was fun with the van going in and out of limp mode with two kids and a wife that had to get back home to make a wedding cake for a customer. I went ahead and change the coil pack, injector and plug on the #3 cylinder. I didn't know which was causing the misfire and didn't want to take it back apart in the middle of a parking lot. I would have thought the code would have showed up sooner than it did. This was in July and the code showed up in October. I learned not to buy Mopar pars off of eBay. They do not have a warranty unless that seller has a receipt where they bought it from the manufacture.

 

[Sienile]

Mopar parts on eBay are fine if the seller is a Mopar dealer. I've gotten a few things from them. I remember I got my rockers from Falls City Mopar on eBay.

It could be that the cat suffered damage but was still operating within its parameters until 3 months later. It's not unusual for a cat to fail a while after a condition that could harm it happens. 20 miles in the mountains, especially if that's uphill, is more than enough to cause damage from excess fuel.

 

[newgrowthcontracting]

I now carry extra parts. I got the O2 sensors and will start with those then to the cat any recommendations on a aftermarket cat? I don't want to spend a thousand dollars on one. When I spoke to Mopar parts warranty they said to get a replacement according to the 2 year warranty They have to contact the seller and the seller have to provide proof of purchase of the part they sold. They have to be a certified parts distributor. There is a lot of black market and counterfeit parts. He said even places like rock auto give them a hard time about providing a purchase receipt from the manufacture.

 

[Sienile]

Any of these should be good. RockAuto has another brand listed (FVP) that I don't recognize and would avoid.

More Information for DAVICO 19583

More Information for AP / EASTERN 641384

More Information for WALKER 16780

 

[Capt W]

There is a lot of P0420 discussion on this and almost every forum. What you have to remember is the code pops up when the catalytic converter falls below a preset efficiency level, and nobody seems to know what that efficiency level is. Could it be 80%? 85%? Who knows?

This is precisely why many folks have added spacers to their downstream O2 sensors in order to remove the sensor tip from direct exhaust flow. This clears the P0420 in most cases. It will not work, however, in states with eyes-on/hands-on emissions inspections (which you stated you don't have).

I don't necessarily disagree with the others here...your problem could be caused by several different things. Most of the time it's a BS efficiency standard and can be cured for 10 bucks in Help! parts.

Well, that didn't work... (using a O2 sensor...

2006 T & C Touring with 3.8 125,000miles Just thought I would share. For the last 3 years my van has been throwing a P0420. After clearing, it would be good for a thousand, then hundreds of miles, then 50 miles before resetting the 420. The car is an oil burner, so I am guessing the cat has...

www.chryslerminivan.net

 

[newgrowthcontracting]

Update the P0420 went off on before changing the sensors so we will see. The voltage does start higher and seems steadier than before.
However while under the van I did find the down stream O2 wires were in a bind. The upstream plug was cracked. I also saw my TC cover and possibly right valve cover are sill leaking oil. I might be going back to the dealership for the fourth time. I took some pictures of both O2s and inside the cat it doesn't look bad to me. In the lower O2 port I did see a scratched spot but I might have done it putting in the camera. The pictures are not great but it was hard to lay on my back hold the borescope steady and take pictures of the screen with my phone.
Upstream O2

DownstreamO2

Upstream cat

Downstream cat

Bank1 sensor 1 and 2

Bank1 and 2 lower sensors

 

[Sienile]

Upstream plug cracked? You mean the port it screws into is cracked? There wasn't any indication of an upstream sensor issue, but that could lead to one.

The downstream sensor looks a bit odd. Toward the base it changes color like it got hot. Not sure if that's dirt or cat material on the tip.

Cat looks fine other than the spot that you mentioned. Unless you've heard rattling from the cat, you're probably right about having scratched it with the camera. But physical condition isn't always a good indicator. Hopefully the new downstream sensor is all it needed.

 

[newgrowthcontracting]

Upstream plug cracked? You mean the port it screws into is cracked? There wasn't any indication of an upstream sensor issue, but that could lead to one.

The downstream sensor looks a bit odd. Toward the base it changes color like it got hot. Not sure if that's dirt or cat material on the tip.

Cat looks fine other than the spot that you mentioned. Unless you've heard rattling from the cat, you're probably right about having scratched it with the camera. But physical condition isn't always a good indicator. Hopefully the new downstream sensor is all it needed.

The white on the tip of the O2 is where I scraped it on the concrete it did have a weird blue green color toward the base. The white plug where the clip is broke apart in my hands when I pulled it apart. You can't see it in the picture it's on the other side. No rattle so I hope this is a fix.
For fun I watched the O2 sensors on our 03 Montero, Bank1 sensors look normal but Bank2 sensor2 the voltage was 0-.020 extremely low and no cat light. I'm guessing I could just change the lower one since it is not as sensitive. The sensors are much more expensive.
Thanks for your help and I will update if it comes back.