Need help with p0420 code - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 7 (permalink) Old 06-27-2007, 01:19 AM Thread Starter
 
Join Date: May 2007
Posts: 12
Need help with p0420 code

Hello everybody.

Let me start off by saying my 97 t-bird has been a great purchse. 197000 miles later it's still running but lately it's been giving me hell for not taking care of it when i should have. I don't blame it.

It all started when I got the following codes.
P0340 - camshaft position sensor a bank 1 circuit malfunction
P0131 - o2 sensor circuit low volts (bank 1 sensor 1)
P0133 - o2 sensor ckt slow response (bank 1 sensor 1)
P1131 - insuff. switching control valve sensor / lean
P0171 - system too lean.
I ran the car for about 6 to 8 months with the check engine light on as the car was not giving any trouble. It was after that I noticed the smell of fuel while the car was running was when I started looking into it and my state inspection was coming up.

Here's what was done to clear these codes.
1. Clean the MAF.
2. Replaced all four oxygen sensors
3. Replaced the camshaft position sensor
4. Replaced teh air and fuel filter

After these repairs the bulb for my check engine light was not working so had to fix that as well. AFter that repair, took it out for a spin and about an hour later it came back on with the following code: p0420 - catalyst efficiency below threshold (bank 1).

I have read posts regardin this code that it could be the oxygen sensor or the catalytic converter. Again, I just replaced all four oxygen sensors. I don't think it makes a differnce but I replaced three of them with bosch sensors and the passenger side before the Catalytic converter with one from the dealership (the cord on teh bosch one listed at the parts store was too short). Bit the bullet and bought it from the dealership as I needed it this past weekend. After making these repairs, the smell of fuel is not as strong as it used to be but it's still present.

Any information / suggestions on how to diagnose this problem would be greatly welcomed.

Thanks,
Alanis
alanis is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 06-27-2007, 11:46 AM
Newbie
Moderator
 
master486's Avatar
 
Join Date: Jun 2006
Location: San Diego
Age: 32
Posts: 5,650
Seeing as how all your oxygen sensors are new, I think that code is legit. The car was running like crap before and who knows how long it has been like that. Most likely the A/F ratio has been off for a while and it destroyed the catalytic converters. The little bit of fuel/rich you smell is probably because of the cats not working as they should. You can replace the whole y-pipe assembly with a magnaflow setup from Summit for around $350 or capitalize on this opportunity and get the whole exhaust done with some high-flow cats.

--Chris

DirtyDog Torque Converter For Sale!!
Huge Parts Sale!!

1996 Thunderbird LX
Awaiting some tender deconstruction...
master486 is offline  
post #3 of 7 (permalink) Old 07-16-2007, 08:26 PM Thread Starter
 
Join Date: May 2007
Posts: 12
hello everybody,
Unfortunately I haven't done anything to fix it. So here we go one more time.

Chris, I definitley agree that the catylic converter on bank 1 (passenger side) is bad. I reset the code and it came back within one hour. Also, the car has a rattling sound that has been verified that it is coming from that same catalytic converter. It definitley needs to get changed.

I'm writing to ask for advice on how to proceed. Chris, I read in your post that I should look into replacing the Y pipe assembly but I'm a little short on cash and I don't want to spend that much cash on this repair as I'm sure that I won't be driving this car within a year. Family got bigger and we need something bigger so more than likely I will be trading this in or selling it. With that said, can I just replace both CATS with universals. If so, will that be enough to clear my p-0420 code.

I ask cause I've been calling around getting quotes on replacing the cats only with universals. Talked with one muffler shop and was told that replacing the cats with universals was not the right way to fix it. Something about flow, blah, blah and that replacing only the cats might not clear the code. Was told by that shop that they will not guarantee from the code coming back going this route. Not sure if this was a bunch of BS in hopes of getting me to replace the Y pipe assembly for $700.

Advice / suggestions are always welcome.

Alanis
alanis is offline  
Sponsored Links
Advertisement
 
post #4 of 7 (permalink) Old 07-16-2007, 09:18 PM
Road warrior extrodinaire

Super Moderator
 
Trunk Monkey's Avatar
 
Join Date: Feb 2006
Location: This Week: Russellville, AR
Posts: 11,801
Garage
Quote:
Originally Posted by alanis View Post
hello everybody,
Unfortunately I haven't done anything to fix it. So here we go one more time.
Take your time and get the right answer to get it fixed right the first time.

Quote:
Originally Posted by alanis View Post
Not sure if this was a bunch of BS in hopes of getting me to replace the Y pipe assembly for $700.

Advice / suggestions are always welcome.

Alanis
I'd say there's your answer. They're just looking to nail you on parts and labor for more work than you really need.

Good Luck. Keep us posted...

Mods? Yea, I got mods ...
Air silencer delete, warp drive, dilithium crystals, flux capacitor, Slingshot Rubber band power adder, Moonshine & Gas, Leaf Blower Supercharger, Hamster Wheel & Hamster, Energizer Bunny generating 1.21 gigawatts, Mr. FusionŽ Home Energy Reactor, hover conversion and a sextant celestial navigation system (The original GPS)
Best 1/4: 1,320 nanoseconds @ 670,616,629.2 miles per hour

"There isn't that much difference anymore between spacecraft, aircraft and modern automobiles..." - Keith Henry, NASA's Langley Research Center
See a list of my real mods and pictures of my car HERE. The true performance of my car was made possible by the Carolinas Crew Chief, RobertP at Rob's Tire & Auto
Trunk Monkey is offline  
post #5 of 7 (permalink) Old 07-16-2007, 09:40 PM Thread Starter
 
Join Date: May 2007
Posts: 12
thanks trunk monkey..

Unfortuntely I need this done ASAP as my inspection sticker has expired since April. this forum has helped me immensely in making the repairs necessary to clear some of the diagnostic codes I got. I now make this my first choice for information concerning diagnostics / repair help.

alanis
alanis is offline  
post #6 of 7 (permalink) Old 07-17-2007, 07:36 PM
Newbie
Moderator
 
master486's Avatar
 
Join Date: Jun 2006
Location: San Diego
Age: 32
Posts: 5,650
It's kind of tricky replacing the catalytic converters on these cars, namely the front 2. The angle of the downpipe going into the converter makes it difficult to just slap on a universal. Some shops will cut the body of the converter right before the catalyst and do the same to the old converter and then weld on the new one, but this is sloppy and doesn't always go right. Other shops fabricate new down pipes and then install the new converter, then connect it to the rest of the system.

You are in a situation where you only need to replace one. This sucks, but it needs to be fixed. The best route is to buy the whole Y-Pipe assembly from Summit or some place similar and install it yourself. It'll be about $350 or so for the assembly. If you can't install it yourself, then take the thing to a shop and have them do it. The labor should only be a couple hours at most because it's not at all difficult to access everything and remove the Y-pipe assembly. The cheapest option would be to find a shop that will make a new downpipe and replace the converter on the side that is bad. It'll also be a couple hours labor but you will only have to replace one converter, which should be around $100 or so depending on which shop you go to.

--Chris

DirtyDog Torque Converter For Sale!!
Huge Parts Sale!!

1996 Thunderbird LX
Awaiting some tender deconstruction...
master486 is offline  
post #7 of 7 (permalink) Old 08-03-2007, 12:01 AM
 
Join Date: Feb 2007
Posts: 64
I ordered a Magnaflow Catalytic converter assembly from performancepeddler.com for $312 w/ free s&h. Put it on myself with a few basic tools in about an hour and a half (no proper way to lift the vehicle & it sits about 4 inches off the ground, slowed me down). This set come made to fit with both of the fronts cats and the 3rd cat included. Nice setup, you might check it out.
mn12v6x2 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome