Hello guys! As you may already know, the Pontiac Vibe is the same exact vehicle as the Toyota Matrix. Anyways, this 2003 Vibe base model AWD had codes P0301 (Cylinder 1 One Misfire Detected) and P0420 (Catalyst System Efficiency below Threshold (Bank 1)) at the beginning. I changed the fuel injector and the P0301 engine code went away. Unfortunately, the P0420 engine code did not go away. I tried erasing the code and driving my Vibe for a while. I wanted to see if P0420 code was a code related to the P0301. Nothing has changed. As of now, when I drive my Vibe for about 15 minutes the light comes as P0420P. P0420P means as you know that there is a pending P0420 and that the CEL will come on in any moment. I was thinking about bad O2 sensors because the Vibe drives fine even with the P0420 CEL on. When there is a bad catalytic converter, the vehicle usually does not run smooth or it feels with no power. But I let the Vibe parked for a while and when I started it, the Vibe had a very bad smell coming from the exhaust. The smell was not gas related but like rare gases. Now, I am confused. I have read a lot online and many people suggest changing the oxygen sensors before changing the catalytic. WHAT YOU GUYS THINK?? Your suggestions will be greatly appreciated!

Another thing, one mechanic also told me that when the catalytic converter goes bad in a car, the P0420 could take even a week or two to show up. In the other hand, when the P0420 is showing due to a sensor, the CEL shows right away (one or two days). What do you thing about this? Thanks!


Updates 10/29/2012: I removed the exhaust as well as the rear O2 sensor. The sensor was kind of dirty and I cleaned with brake cleaner. As far as the CAT, I tried something that heard about cleaning it with Lacquer Thinner. I used a full gallon on the CAT, but it did not help. After putting everything back together and running my Vibe for a while, I scanned the Vibe for CEL codes and I was still getting a pending P0420P. After driving for more time, the CEL came back on.


Tags: 03 04 05 06 07 08 2003 2004 2005 2006 2007 2008 GT GTR Matrix eggs

 

Anybody?

 

Maybe it would be good if you went onto a pontiac/toyota forum.. Just saying.

 

I figured that. However, these are symptoms that any car could have. I know that you guys have great answers!

 

p0420 is caused by low converter efficiency. It uses a narrowband sensor post cat and the ecu looks to see if the signal fluctuates like a precat sensor would. If the cat is good, it would stay constant around .450 to 600mv, as the oxygen content would be constant.

Do you have access to a scanner which would allow you to monitor the post cat oxyen sensor?

If you do, check to see if the post cat sensor fluctuates. If it does, try revving the car for 2-3 min. at 2000rpm in an attempt to "relight" the cat. If that doesn't work, then try a long uphill climb in 2nd gear in attempt to relight the cat. The post cat sensor will spike to 900+ mv under open loop heavy load as the exhaust is quite rich. However, after that initial relight, it should come to a constant while cruising with 50-100mv+/-.

Try that first, it has worked for me a couple times. When I lived in Ontario, I was a DriveClean tech (EPA). That was my sole purpose in the world, diagnosing emmisions faults/failures.

 

Wow! This sounds very professional. I do not really have access to a scanner to monitor the pre-CAT O2 sensor. However, I will definitely try to get one to follow your theory. That is why I like Honda-Tech, there are always professionals to help us out! I will try your theory!

 

Sporty Aztec! lol

 

LOL! The Aztec looks ugly to me. This little car is great though. It is great in gas, spacious, all wheel drive, and the most important thing is that the Vibe has a 1.8L DOHC VTT-i Japanese engine and tranny (Toyota to be more specific). It is the same as the Matrix. It is also good to mention that many people online likes more the Vibe over the Matrix..

 

Usually if you have a bad O2 sensor it will throw a O2 sensor code. Being that it's just a cat code sounds like you have a bad cat.

Interesting fact: As far as compact cars go. The Pontiac Vibe was one of the best compact cars General Motors every made, and the Toyota Matrix was one of Toyota's worst. LOL

 

Yes, you are very right. It is crazy but many online sources point out to a bad 2nd O2 sensor.

LOL... Very nice fact... It is crazy how this works. I am surprised that the Matrix is one of the worst Toyotas every made when the Matrix has the same engine as the 2003-2008 TOYOTA COROLLA and other Toyotas which have been very successful and reliable. It is crazy Well, I am Honda 100%... This is my first Toyota/Pontiac vehicle; I hope that this is a good vehicle...

 

No doubt it will be a good vehicle. They're not known for many problems. I don't know if Vibe has the same recall, but Toyota has a recall for the pcm for matix's and corolla's.

 

Yes Sir, I read about it. It is actually for having this same P0420 code recorded even when there is not cel present...

 

www.genvibe.com


GLD. Former 03 Vibe owner.

 

Yes, thank you for the suggestion. I am actually already subscribed to that website and posted a thread about this same problem.

 

Anybody has ever install an aftermarket CAT? If so, which brand and how does it work?

 

This is so confusing. After driving even for 10 minutes and having the CEL reset, I have a CEL rescan and I P0420P. To my understanding this code is a pending P0420. The Vibe practically shows this P0420P code right away. After certain amount of miles t is when I get the P0420 code accompanied by the P0420P as well. Any other ideas based on this?

 

I noticed that the rear muffler tip is very, very smoke dirty in the inside. So, if the catalytic and sensors are as dirty as the exhaust tip, all components inside the exhaust should be clogged and dirty.

 

Updates 10/29/2012: I removed the exhaust as well as the rear O2 sensor. The sensor was kind of dirty and I cleaned with brake cleaner. As far as the CAT, I tried something that heard about cleaning it with Lacquer Thinner. I used a full gallon on the CAT, but it did not help. After putting everything back together and running my Vibe for a while, I scanned the Vibe for CEL codes and I was still getting a pending P0420P. After driving for more time, the CEL came back on.

 

I was also suggested to try a defouler on the O2 sensor, but I do not think that this would help me that much...

 

I am going to install the defouler. If the CEL does not come back, I would not for sure that I need to replace the CAT.

 

I am going to install the defouler. If the CEL does not come back, I would know for sure that I need to replace the CAT. I am just trying to troubleshoot it using the defouler. I am going to install the defouler to test the Catalytic. If the CEL does not come back, I would know for sure that I need to replace the CAT. In the other hand if the light comes back on even with the defouler, then I would know that the CAT sensor is not good.

 

The defouler worked. The CEL went off. Even the OBD2 scanner says that the car is ready for inspection. This is great, I know now that the problem is really the CAT and not the sensor. I am now ready to change the Catalytic to be ready for inspection!