Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1987 - 1996 F150 & Larger F-Series Trucks
Sign in using an external account
Register Forgot Password?


1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 05-05-2010, 04:35 PM
oldblu65's Avatar
oldblu65 oldblu65 is offline
Junior User
 
Join Date: May 2009
Posts: 50
oldblu65 is starting off with a positive reputation.
Code PO420 !

Truck is a 1996 F150 , 4.9L/5 speed OD ,1/2 ton ! On and off problem , on again ! Scanned PO420 -" Catalyst efficiency low-bank 1" ! Both O2 sensors have been replaced ( 3 months ago ) , throttle body cleaned , IAC valve cleaned , MAF sensor cleaned , new thermostat , new plugs and wires , new distributor cap , new PCV valve , and new fuel filter . Scan list of probable causes are # 1 -Cat conv. defective ( possibly because of # 2,# 3, or # 4 ) . # 2 -engine misfire or running condition . # 3 - large vacuum leak , or # 4 - engine oil leakage into exhaust-valve guide, seals , or piston rings . ( # 2 ) - Engine does seem to have a slight miss and seems to slightly stumble under acceleration and does not have much power . ( # 3 ) - Have already replaced several small vacuum hoses because of tiny cracks and can not find any major leaks ? ( # 4 ) - Engine does not smoke or use oil . It does have one strange habit - the engine temp gauge normally runs ( when at operating temp. ) slightly below the mid point . Occasionally , the idle will hover around 1200 rpms and when this happens , the gauge will show the temp going up top about 3/4 on the temp gauge . That usually happens in slow traffic and tends to get me very nervous ! When the engine idles at it's normal range , the temp seems to stay in the appropriate range . The TPS switch has not been replaced . I live where emission tests are done and this is my month to renew my tags ! The " check engine " light and the cause of it have to be repaired before the end of the month ! I was hoping to fix it myself but may have to take it to a professional if I can't figure it out soon . Any and all help will be truly appreciated !
Reply With Quote
  #2  
Old 05-06-2010, 01:32 PM
Lazy K Lazy K is offline
Post Fiend
 
Join Date: Jan 2005
Posts: 8,402
Lazy K is a name known to allLazy K is a name known to allLazy K is a name known to allLazy K is a name known to allLazy K is a name known to allLazy K is a name known to all
Not an expert but if nothing else this will bump.
A few causes, bad cat or exhaust leak or fuel pressure too high or defective wiring to downstream oxygen sensor or bad engine coolant temperature sensor.
Reply With Quote
  #3  
Old 05-07-2010, 03:22 PM
oldblu65's Avatar
oldblu65 oldblu65 is offline
Junior User
 
Join Date: May 2009
Posts: 50
oldblu65 is starting off with a positive reputation.
Anyone have any suggestions ?
Reply With Quote
  #4  
Old 05-10-2010, 03:37 PM
oldblu65's Avatar
oldblu65 oldblu65 is offline
Junior User
 
Join Date: May 2009
Posts: 50
oldblu65 is starting off with a positive reputation.
Anyone have a similar experience ?
Reply With Quote
  #5  
Old 05-12-2010, 01:55 AM
oldblu65's Avatar
oldblu65 oldblu65 is offline
Junior User
 
Join Date: May 2009
Posts: 50
oldblu65 is starting off with a positive reputation.
Help Please !
Reply With Quote
  #6  
Old 05-12-2010, 05:42 AM
dustybumpers's Avatar
dustybumpers dustybumpers is offline
Posting Legend
 
Join Date: May 2008
Location: In my own world
Posts: 52,350
dustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputation
check fuel pressure, you may have a bad regulater, and pressure is too high. does your oil smell like gas? if you have a fuel problem, it will burn out the cat. hit the bottom of your muffler with your hand to see if it rattles, like pieces of the cat are caught inside. do this when it's cold though so it don't burn your hand
__________________
Quote:
Originally Posted by donjamer View Post
Oh OK... Just wasn't sure..Seeing you had Rob with his panties around his ankles and then the talk of a new toy...

Charlie slackmaster #26
"A common mistake people make when trying to design something completely fool proof, is to underestimate the ingenuity of a complete fool."
Reply With Quote
  #7  
Old 05-26-2010, 05:01 PM
oldblu65's Avatar
oldblu65 oldblu65 is offline
Junior User
 
Join Date: May 2009
Posts: 50
oldblu65 is starting off with a positive reputation.
Code PO420 !

I had the catalytic converter replaced today and it made a huge difference in the way it runs ! The unit was apparently the original one ( 180,000 miles ! ) and it was disintegrated inside ! The second converter was full of debris from the first one and the muffler shop guy said the second one was the California required unit and not needed in our area ! So it was removed and replaced with a straight pipe . I went straight to the emission testing station and passed with flying colors ! Thanks for the help from all !
Reply With Quote
  #8  
Old 05-26-2010, 08:26 PM
dustybumpers's Avatar
dustybumpers dustybumpers is offline
Posting Legend
 
Join Date: May 2008
Location: In my own world
Posts: 52,350
dustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputationdustybumpers has a superb reputation
good deal, glad to help
__________________
Quote:
Originally Posted by donjamer View Post
Oh OK... Just wasn't sure..Seeing you had Rob with his panties around his ankles and then the talk of a new toy...

Charlie slackmaster #26
"A common mistake people make when trying to design something completely fool proof, is to underestimate the ingenuity of a complete fool."
Reply With Quote
  #9  
Old 05-27-2010, 01:29 AM
79n40z 79n40z is offline
Junior User
 
Join Date: Jun 2009
Posts: 51
79n40z is starting off with a positive reputation.
so did this get rid of the CEL...

I have the same code on mine and gone through the same steps.

I have checked everything except the cat.

I tried also the banging to listen for a rattle and NO dice. It sounds very solid. I HATE CATALYTIC CONVERTERS these ba$+ards are like $80
Reply With Quote
  #10  
Old 05-27-2010, 01:37 AM
andym's Avatar
andym andym is offline
Post Fiend
 
Join Date: Mar 2002
Location: Sacramento, CA
Posts: 16,486
andym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputationandym has a superb reputation
Don't complain. I was getting the same code on my Civic and ended up having to replace the cat at a cost of about $1100. It would not pass the sniffer test without it.
__________________
Andy

2000 Excursion Limited 7.3L 4x4

"If you want to live in a country that manufactures things, you need to buy things that your country manufactures." - Mike Rowe
Reply With Quote
  #11  
Old 05-27-2010, 03:07 PM
oldblu65's Avatar
oldblu65 oldblu65 is offline
Junior User
 
Join Date: May 2009
Posts: 50
oldblu65 is starting off with a positive reputation.
The muffler shop guy deals with lots of converter replacement and does his own code scans . He turned the CEL off after finishing the job and so far it hasn't come back on . The thought of shaking the converter to listen for rattles doesn't always work according to the muffler guy . The converter can be semi-plugged , basically stopped up , or contaminated to the point of destroying it's ability to do it's job and not make a rattling sound but still be bad . My particular situation was the exhaust system was properly secured and there wasn't enough movement in the mounting points to allow " shaking " the converter .
Reply With Quote
  #12  
Old 05-27-2010, 06:57 PM
Virto's Avatar
Virto Virto is offline
Posting Guru
 
Join Date: Jun 2007
Location: Des Plaines, Illinois
Posts: 1,394
Virto has a good reputation on FTE.Virto has a good reputation on FTE.Virto has a good reputation on FTE.
Quote:
Originally Posted by andym View Post
Don't complain. I was getting the same code on my Civic and ended up having to replace the cat at a cost of about $1100. It would not pass the sniffer test without it.
Tell me about it. I just had one replaced on the I30 and it was 700 bucks.

My mom was told her 99 Cougar needed cats. It has THREE of them!
__________________
Quote:
Originally Posted by Silver Streak View Post
You're having problems because some butthole put the wrong one on your truck.
1990 Ford F-150 XLT Lariat Supercab - 5.0/E4OD - Dead and gone.
1993 Ford F-150 XLT Supercab - 5.0/AOD - 3.55
Reply With Quote
  #13  
Old 05-27-2010, 08:21 PM
twavor twavor is offline
Freshman User
 
Join Date: Nov 2003
Location: South Central IA
Posts: 41
twavor is starting off with a positive reputation.
Wish I would have seen your thread earlier....P0420 almost always means that you need the Cat replaced. I send everyone to the local muffler shop, they can usually replace any truck cat for around $150 total. They will usually take the cat out, look inside, call me and say "That cat aint plugged up!"....and I'll say, "I know, just replace it, please".
Anyway, P0420 means that the cat isn't doing what it's supposed to do and the O2 sensor right behind it knows that it's flowing too freely and sends the message to the PCM and sets the code.
Personally, I think it's a stupid code and the OEM's (and possibly the govt.) should really loosen up the criteria for the PCM setting the code.

Travis
Reply With Quote
Old 05-27-2010, 08:21 PM
 
 
 
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
99 5.4 CEL and weird idle issues tinman52 Super Duty & Heavy Duty 7 03-05-2013 08:56 AM
Scan Gauge Owners, Help me with some temps mrad Excursion - King of SUVs 8 09-19-2010 01:24 PM
Chasing a demon... Archion 1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks 3 07-22-2010 07:40 AM
Can a bad engine temp sensor cause a high or changing idle?? weswes01 Cooling, Heating, Ventilation & A/C 1 11-12-2007 10:08 PM
P0171,P0174 CEL Light 98 Ranger 4.0L pill90 Ranger & B-Series 25 01-02-2007 06:07 PM


Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1987 - 1996 F150 & Larger F-Series Trucks

Tags
1996, 2002, 2005, 2009, 420, 49l, 68, code, f150, f250, f350, ford, p0420, po420, truck

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump


Participate In The Forums

Create new posts and participate in discussions. It's free!

Sign Up »





All times are GMT -5. The time now is 01:29 PM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup