Error P0420 vacuum leak? - Nissan Forums : Nissan Forum
 
LinkBack Thread Tools Display Modes
#1 Old 10-30-2009, 11:59 AM
Registered User
 
Trav-0's Avatar
 
Join Date: Nov 2008
Location: Upstae NY
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
(Thread Starter)
Error P0420 vacuum leak?

Okay, so my check engine light came on at 128000 miles in my 2001 Altima. The car has been running like a champ despite some unrelated suspension issues.

The error code I get is a P0420 Catalyst system efficiency below threshold.

The car has been burning a little bit of oil and at the time I checked it was actually about 1/8 quart over which I could probably attribute to expansion due to heat. Other than that I haven't noticed any rotten egg smell from the tail pipe and everything seems to be running correctly.

The probable cause here says.
Large Vacuum Leak
Fuel System Fault
Ignition System Fault
Failed Bank 1 Catalytic Converter

I am limited in knowledge but can handle everything but the vacuum leak.

#1) Where are ALL the vacuum lines to check
#2) How do I check them
#3) If leak is found how do I replace them

I have the Nissan factory manual, the good one for mechanics, but can't seem to find where the vacuum lines are,

Any help is greatly appreciated.
Trav-0 is offline  
Sponsored Links
Advertisement
 
#2 Old 10-30-2009, 02:46 PM
ewwfffff...another altima
 
rtkskater44's Avatar
 
Join Date: Sep 2008
Location: clinton, ct
Posts: 1,902
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
i highly doubt it would be vacuum leak... unless you see fluctuation in your idle / poor gas mileage, it would be a clogged cat or sumthing along the exhaust.. maybe bad 2nd o2 sensor... do u have headers or is your car complete stock?







soon to be under massive construction.....


rightnow... master minding my '93 altima gxe.
rtkskater44 is offline  
#3 Old 10-30-2009, 02:51 PM
Registered User
 
Trav-0's Avatar
 
Join Date: Nov 2008
Location: Upstae NY
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
(Thread Starter)
This car is totally bone stock, I aim to get the thing in the air and check the secondary O2 sensor sometime tomorrow or Sunday with a multimeter.

There is no fluctuation in the idle but it sounds like there is some back pressure in the exhaust with lots of black soot on the end of the muffler. The gas mileage has been an issue since I have owned the car, but since my inspection expires at the end of the month it has kind of become an issue to get that CEL off.

Please advise? Thanks again.

Oh, the only reason why I suggest vacuum is because it is the thing I know the least about and figure it can't hurt to check it.
Trav-0 is offline  
#4 Old 10-30-2009, 03:08 PM
The Don.
 
Join Date: Jul 2002
Location: Northern VA
Posts: 6,126
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Thanks: 2
Thanked 42 Times in 29 Posts
iTrader: 1 reviews
With your issue the term "vacuum leak" is incorrect. It should say, "exhaust leak".

An exhaust leak can play havoc with the front or rear O2 sensor. If those sensors are reading incorrect data then the diagnostic that goes out to check the condition of the catalytic converter will also report a false code.

The easiest way to pinpoint an exhaust leak is to have someone cover up the tailpipe with some rags while you listen closely along the exhaust pipes.



'94 Nissan Altima SE, 5spd.
Erebuni 905, Turboing, Hotshot CAI, UR Pulley, Calum ECU,
HUD & ATC retrofitted, DEPO lamps, NGK Ignition wires.
ITEMS FOR SALE
jserrano is offline  
#5 Old 10-30-2009, 03:11 PM
ewwfffff...another altima
 
rtkskater44's Avatar
 
Join Date: Sep 2008
Location: clinton, ct
Posts: 1,902
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
welcome jserrano =],
he is our premium mech diagnostic specailist, he came. he saw. he conquered..

everyone give him a round of applause!!!
thank you thank you







soon to be under massive construction.....


rightnow... master minding my '93 altima gxe.
rtkskater44 is offline  
#6 Old 10-30-2009, 03:25 PM
The Don.
 
Join Date: Jul 2002
Location: Northern VA
Posts: 6,126
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Thanks: 2
Thanked 42 Times in 29 Posts
iTrader: 1 reviews
Quote:
Originally Posted by rtkskater44 View Post
welcome jserrano =],
he is our premium mech diagnostic specailist, he came. he saw. he conquered..

everyone give him a round of applause!!!
thank you thank you
Damn, I hadn't noticed I gained that much notoriety.

Actually, I only understand some areas more than other, and mainly they have to do with electrical or electronic control systems. If I were ever to enter into the auto mechanics field it would have been as a Drivability Technician. But I enjoy my work as a Database Administrator too much. I guess this is good enough for me as a hobby.



'94 Nissan Altima SE, 5spd.
Erebuni 905, Turboing, Hotshot CAI, UR Pulley, Calum ECU,
HUD & ATC retrofitted, DEPO lamps, NGK Ignition wires.
ITEMS FOR SALE
jserrano is offline  
#7 Old 10-30-2009, 04:17 PM
Registered User
 
Trav-0's Avatar
 
Join Date: Nov 2008
Location: Upstae NY
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
(Thread Starter)
Well thank you jserrano and rtkskater44 I will take a look and see what I can figure out. If this doesn't help to alleviate the problem I know I will be back but this at least will give me a good start on what to look for.
Trav-0 is offline  
#8 Old 06-30-2011, 11:30 PM
Registered User
 
Trav-0's Avatar
 
Join Date: Nov 2008
Location: Upstae NY
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
(Thread Starter)
Turned out to be a bad catalytic converter. In the meantime I replaced both o2 sensors, cleaned the EGR, tracked all the vacuum lines down and put about 25,000 on her.
Trav-0 is offline  
#9 Old 07-02-2011, 02:51 PM
97AltimGXE
 
1997GXE's Avatar
 
Join Date: Jul 2006
Posts: 612
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 1 Time in 1 Post
iTrader: 1 reviews
which cat was it? i have the same code also...the 02 sensors were changed in 2006....



Mod List
Place Racing Intake with k&n filter
SE Sides
Erebuni 905 rear
Falken Ziex ZE-912
98 alty 6 spoke alloy rims
UR Pulley
JDM smoked tail lights
IBI Eyelids
93-94 Grill


* New Pics to come Soon*
1997GXE is offline  
#10 Old 07-04-2011, 08:47 PM
Registered User
 
Trav-0's Avatar
 
Join Date: Nov 2008
Location: Upstae NY
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
(Thread Starter)
Quote:
Originally Posted by 1997GXE View Post
which cat was it? i have the same code also...the 02 sensors were changed in 2006....
There is only one that is integrated into the header. Mine is not a CA model.

These engines if driven into the high 4000's can and will burn out the cat. The catalyst will melt and it will clog. It's a piss poor design. If you can and have all the tools you can get an inline one for much cheaper but you will need to cut and weld and hope that you have enough slack in your secondary o2 sensor to get it to fit in still.

Much less work just pulling the fan shroud and fans, removing heat shield, taking header bolts out, disconnecting all the bottom of the pipe, removing primary o2 sensor (better safe than needing a $60 o2 replacement), loosening the alternator and getting the 6 bolts that old the cat on. If you do it you will need a 10, 12, 14, and 15 mil socket and 2 8" extensions at the very least.

Best way to tell if you need a cat is to ride behind yourself and see if it smells like rotten eggs. If it does then you will need a new cat. Course... you can't follow yourself so just have someone else drive and follow.

Hope that helps.
Trav-0 is offline  
#11 Old 07-05-2011, 12:42 AM
97AltimGXE
 
1997GXE's Avatar
 
Join Date: Jul 2006
Posts: 612
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 1 Time in 1 Post
iTrader: 1 reviews
hey thanks for the info... it doesn't smell like rotten eggs.. last year the same code came on but went away within a few weeks. should i change my 02 sensors....



Mod List
Place Racing Intake with k&n filter
SE Sides
Erebuni 905 rear
Falken Ziex ZE-912
98 alty 6 spoke alloy rims
UR Pulley
JDM smoked tail lights
IBI Eyelids
93-94 Grill


* New Pics to come Soon*
1997GXE is offline  
#12 Old 07-05-2011, 01:02 AM
Registered User
 
Trav-0's Avatar
 
Join Date: Nov 2008
Location: Upstae NY
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
(Thread Starter)
Guess that depends on how many miles since you replaced them in 2006. Usually if it's an o2 sensor it will be a code that is specific to the o2 sensors. Something like a P0130-P0167 which would indicate that an o2 sensor is bad.

A P0420 could be an indicator of what was mentioned above. What I would do is get some spark plug anti-foulers and use those to fool the computer.

If you follow the guide below be warned that it is a temporary solution but costs very little. If the light goes out I would lean towards replacing the catalytic converter. If it doesn't I would say that it is possible that you have an exhaust leak or a vacuum leak.

Guide --> http://www.energeticforum.com/renewa...n-foulers.html

List of codes --> OBD-II Check Engine Light Trouble Codes

If I recall correctly your secondary o2 sensor on that car is a weird size that a sparkplug anti-fouler will not work. If that is the case then you need to find another way.

Last edited by Trav-0; 07-05-2011 at 01:06 AM.
Trav-0 is offline  
Sponsored Links
Advertisement
 
Reply

  Nissan Forums : Nissan Forum > Nissanclub.com Nissan - Infiniti Enthusiast Forums > NISSAN ALTIMA FORUMS > 1993-2001 Nissan Altima Forums > General Nissan Altima Discussion (1993-2001)

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Nissan Forums : Nissan Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


<

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

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