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Joined: Oct 2014
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raffaello
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raffaello Jul 24, 1:21pm - #450688 
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Joined: Oct 2014
Posts: 6
San Francisco, CA
Catalytic Converter Bad? Diagnose with OBD scanner and Excel

Hi, Mates

I think my catalytic converter is bad?
Please look at my excel data.

I read and watched on Youtube that O2 Bank 1 Sensor 1 should fluctuate between 0.00V and 0.90V
O2 Bank 1 Sensor 2 should be stable somewhere around 0.45V the entire time.

For those that don't know, Sensor 1 is before the Cat, and Sensor 2 is after the Cat.

I used Scan Tools USB device and OBDwiz software to record the data.

Cat Data.xlsx
https://www.dropbox.com/s/1cl1t1ytasj6mhq/Cat%20Data.xlsx?dl=0 (Sorry, fixed link)


BTW, my engine is leaking somewhere either from the back or from the oil pan.
Haven't been able to find out the problem yet.


· Catalytic Converter OBD Data
CatData1.PNG
· Catalytic Converter OBD Data 2
CatData2.PNG
· Cat Data3
CatData3.PNG
Joined: May 2002
Posts: 422
CaffeineKid
CelicaSpecialist
CaffeineKid Jul 24, 1:24pm - #450689 

CelicaSpecialist
2008 Scion tC

Joined: May 2002
Posts: 422
California
What warning codes is your obd2 reader displaying?
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Posts: 6
raffaello
New Member
raffaello Jul 24, 1:47pm - #450690 
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Joined: Oct 2014
Posts: 6
San Francisco, CA
P0420 of course
And a pending 0446

· Trouble codes
Trouble Codes.PNGFreeze Frame.PNG
Joined: Oct 2014
Posts: 6
raffaello
New Member
raffaello Jul 24, 2:28pm - #450691 
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Joined: Oct 2014
Posts: 6
San Francisco, CA
I wasn't even aware of the P0446, which is completely new to me.
I found this great resource talking about the Bypass VSV that seems to fail often on the 00-02 Celica
http://www.newcelica.org/forums/showthread.php?t=253453
Joined: Oct 2014
Posts: 6
raffaello
New Member
raffaello Jul 24, 3:07pm - #450692 
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Joined: Oct 2014
Posts: 6
San Francisco, CA
I have a 2001 Toyota Celica GT-S, 168K miles
Joined: May 2002
Posts: 422
CaffeineKid
CelicaSpecialist
CaffeineKid Jul 24, 3:13pm - #450693 

CelicaSpecialist
2008 Scion tC

Joined: May 2002
Posts: 422
California
P0420 is often because of a faulty fuel cap gasket -- or if the fuel cap was not tightened to a good seal when you last put fuel in your vehicle.

1. Tighten your fuel cap.
Or
2. If when you remove your cap, you dont get a gush of pressure release, replacing the fuel cap will also clear up the code within a matter of miles.


EDIT:
Often, the P0420 will trigger another "O2 Bank x Sensor x" related warning. Fix the P0420, and the other may also disappear.

P0441 & P0455 are also related to each other.
Joined: Oct 2014
Posts: 6
raffaello
New Member
raffaello Jul 24, 3:25pm - #450694 
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Joined: Oct 2014
Posts: 6
San Francisco, CA
I don't hear it often. I filled up today and will drive a lot this weekend so I will check again. Maybe the code will go away.

I have been reading that the O2 Bank 1 Sensor 2 data should be stable.
Mine is not, which leads me to believe the Cat really is bad.

I should say that I put a new fuel pump in a while back, but that wasn't the problem (Ignition coil ground was loose, causing all sorts of problems) so I put the old fuel pump back. But I busted an o-ring, so I had to get a new one. Before I got the new o-ring, my fuel pressure was miserable. I would have to turn the car over for 5+ seconds before fuel finally made it to the injectors. If I left it for more than a few hours, all pressure was lost. Once I replaced, it was much better, but I still felt that it is lacking.

I replaced the o-rings for the fuel injectors a while ago.
I also replaced those rubber gaskets on the fuel injectors that go into the engine and spray fuel a few weeks ago hoping to get some better pressure and it helped somewhat. Starting the engine could be a little better than it is now.

i feel like going to find a Celica for sale and ask the guy if I can run diagnostics on it and offer $20 while he drives just for data comparison.
Joined: May 2002
Posts: 422
CaffeineKid
CelicaSpecialist
CaffeineKid Jul 24, 3:30pm - #450695 

CelicaSpecialist
2008 Scion tC

Joined: May 2002
Posts: 422
California
Originally Posted by raffaello
i feel like going to find a Celica for sale and ask the guy if I can run diagnostics on it and offer $20 while he drives just for data comparison.


Thats an interesting idea. Or check http://usedcars.automobilemag.com/toyota/celica/ for something local at a used-car lot, and get the job done with no out-of-pocket to you.
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