P0420 - Precat - Nissan Forums : Nissan Forum
 
LinkBack Thread Tools Display Modes
#1 Old 12-08-2009, 12:58 AM
Registered User
 
Join Date: Dec 2009
Posts: 3
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)
P0420 - Precat

The other day I was out on a roadtrip in my 2004 Altima 2.5 with 83000 miles when the SES light suddenly illuminated. 350 miles later I was back home and went straight to a dealer who confirmed it was code P0420 for a bad precat. I ended up having a new precat installed. I've since done a lot of browsing on this forum and read all of the horror stories associated with this problem and in many cases the resulting engine damage.

I'm curious as to how many people here have had the P0420 SES from a bad precat, then either replaced the precat with a new one or an aftermarket header, and have NOT had to replace the engine later on. I have yet to experience any of the obvious signs of engine damage, including excessive oil consumption. But then again, the P0420 code was only thrown about 400 miles ago and I imagine that if any of the precat DID make its way into the engine I may not be seeing the full effect of it just yet.

Finally, is there anything more I can be doing at this point to either prevent engine damage or determine if it's already been done? Would a compression test or early oil change be worthwhile at this point?
lh2005 is offline  
Sponsored Links
Advertisement
 
#2 Old 12-08-2009, 01:34 AM
Registered User
 
Join Date: Aug 2009
Posts: 574
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 2 Times in 1 Post
iTrader: 0 reviews
I know its probably torturing you, but I think you have to wait it out to see if anything is in their scoring your cylinder walls, which causes the oil loss. 400 miles may be too early to tell.

Was the precat covered under warranty?

trooplewis is offline  
#3 Old 12-08-2009, 02:02 AM
Registered User
 
Join Date: Dec 2008
Location: Toronto, Canada
Posts: 31
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
For peace of mind

Quote:
Originally Posted by lh2005 View Post
The other day I was out on a roadtrip in my 2004 Altima 2.5 with 83000 miles when the SES light suddenly illuminated. 350 miles later I was back home and went straight to a dealer who confirmed it was code P0420 for a bad precat. I ended up having a new precat installed. I've since done a lot of browsing on this forum and read all of the horror stories associated with this problem and in many cases the resulting engine damage.

I'm curious as to how many people here have had the P0420 SES from a bad precat, then either replaced the precat with a new one or an aftermarket header, and have NOT had to replace the engine later on. I have yet to experience any of the obvious signs of engine damage, including excessive oil consumption. But then again, the P0420 code was only thrown about 400 miles ago and I imagine that if any of the precat DID make its way into the engine I may not be seeing the full effect of it just yet.

Finally, is there anything more I can be doing at this point to either prevent engine damage or determine if it's already been done? Would a compression test or early oil change be worthwhile at this point?
I would just get a compression test and go from there. I lost many nights of sleep over this and just decided to swap out the oem header for an aftermarket one.
Shooter99 is offline  
#4 Old 12-08-2009, 02:56 AM
Biz
VQ'D Sleeper
 
Biz's Avatar
 
Join Date: Apr 2009
Location: Utah
Posts: 335
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
Do you like your Altima and plan to keep it for a few years? If your answer is no, then do nothing. Monitor oil usage and when it starts to increase trade it in or sell. If you want to keep it, replace the exhaust manifold with a good quality catless header asap. Sleep better at night and enjoy the added boost of power.

2003 3.5 4AT

Racingline | Nismo | Optima | Weapon-R | Stillen | Raybestos | BT | 4DZC | VLEDS
Biz is offline  
#5 Old 12-08-2009, 04:01 AM
Registered User
 
Join Date: Aug 2009
Posts: 574
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 2 Times in 1 Post
iTrader: 0 reviews
Quote:
Originally Posted by 03Alt3.5Biz View Post
Do you like your Altima and plan to keep it for a few years? If your answer is no, then do nothing. Monitor oil usage and when it starts to increase trade it in or sell. If you want to keep it, replace the exhaust manifold with a good quality catless header asap. Sleep better at night and enjoy the added boost of power.
I think it's too late for that since his original cat already went out, and now he is just trying to figure out if it damaged his engine in the process.

It would have been nice if the dealer had said what kind of condition the original cat was in when they removed it, that might have helped.

trooplewis is offline  
#6 Old 12-08-2009, 02:15 PM
Registered User
 
Join Date: Dec 2009
Posts: 3
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)
Thanks for the replies everyone. I did ask the dealer about the condition of the precat and the possibility of engine damage, and the service rep simply said the mechanic didn't indicate that there was any. The garage had already closed up for the day when I went to pick up the car, but in retrospect I should have asked to see the old precat myself. I'm going to make some calls and try to determine exactly what that old precat looked like.
lh2005 is offline  
#7 Old 03-23-2010, 04:10 PM
Registered User
 
Join Date: Mar 2010
Posts: 6
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
I to own a 2002 2.5 altima.At 110k miles the service engine lite came on.It was po420.I reset the light but it came on again the following week.Not knowing about the damage it could cause,i ignored it for 2 years.The car now has 130k,use's no oil and runs like a top.Now that i have found this forum,it's hard to sleep at night.I think i'm going to get the mil eliminators,clean out the precat,and keep driving.
craftsman74066 is offline  
#8 Old 03-23-2010, 04:26 PM
Registered User
 
Join Date: Apr 2009
Posts: 531
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
iTrader: 0 reviews
I believe if any pieces do get re-circulated into the engine they must do so through the EGR system? (someone correct me if I'm wrong) At least on the 3.5VQ, it's just as common to get EGR valve codes because little bits of catalytic converter are stuck up there as a actual 02/cat code. So you could pull your EGR valve and see if there's any random particles in there. It's possible that if there is, you can pull them out and save yourself any future damage.
Compression test is the best way to check out the health of your piston rings. The gauges are cheap (~$50) so I would suggest buying one yourself and learning how to use it. It's a great diagnostic tool. Just remember to always do a compression test with the engine warm. (all parts heated up and fully expanded/seated) Doing a compression test on a cold engine can sometimes yield some scary results and lead you to spend money and perform repairs that may not be necessary.
A cylinder leak down tester is a good tool to have as well. You rotate the crankshaft until the valves are closed on each cylinder (one at a time) and then you pressurize the cylinder with compressed air. If the gauge on the tester does not hold, you are leaking that air out of the engine somewhere. If it's escaping past the piston rings, you'll usually find that the air is coming out through the dipstick tube. If a intake valve/seat is bad, the air will come out somewhere like the intake manifold. If a bad exhaust valve/seat, it'll come out the tailpipe. A piece of tissue paper or equivalent is good to use to help detect any air flow because sometimes the amount can be small and not detectable by "feel".

2005 Altima SER

Modifications:
Racingline Y-Pipe
swamper8 is offline  
#9 Old 03-24-2010, 05:14 AM
2010 2.5s Sedan
 
jimnolimit's Avatar
 
Join Date: Aug 2006
Location: brooklyn
Posts: 5,140
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 1 Time in 1 Post
iTrader: 0 reviews
Quote:
Originally Posted by lh2005 View Post
The other day I was out on a roadtrip in my 2004 Altima 2.5 with 83000 miles when the SES light suddenly illuminated. 350 miles later I was back home and went straight to a dealer who confirmed it was code P0420 for a bad precat. I ended up having a new precat installed. I've since done a lot of browsing on this forum and read all of the horror stories associated with this problem and in many cases the resulting engine damage.

I'm curious as to how many people here have had the P0420 SES from a bad precat, then either replaced the precat with a new one or an aftermarket header, and have NOT had to replace the engine later on. I have yet to experience any of the obvious signs of engine damage, including excessive oil consumption. But then again, the P0420 code was only thrown about 400 miles ago and I imagine that if any of the precat DID make its way into the engine I may not be seeing the full effect of it just yet.

Finally, is there anything more I can be doing at this point to either prevent engine damage or determine if it's already been done? Would a compression test or early oil change be worthwhile at this point?
1. do a compression test
2. monitor oil consumption .

you might want to also consider changing the butterfly valve screws and loctiting them , search butterfly valve screws .
jimnolimit is offline  
Sponsored Links
Advertisement
 
Reply

  Nissan Forums : Nissan Forum > Nissanclub.com Nissan - Infiniti Enthusiast Forums > NISSAN ALTIMA FORUMS > 2002-2006 Nissan Altima Forums > 2002-2006 Nissan Altima Discussion (2.5 & 3.5)

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