P0300 Code Please Help! - Page 2 - Mazda Forum - Mazda Enthusiast Forums


Mazda Protege This compact model offers an economical solution for the need for a sporty sedan or wagon.

Reply
 
 
 
Thread Tools Search this Thread
  #11  
Old 10-07-2008, 02:45 PM
 
Join Date: Oct 2008
Posts: 1
Default RE: P0300 Code Please Help!

I have a '02 Mazda Protege 5 with a similar problem (diagnostic code P0300 and P0421). Originally I had a problem with the catalyst converter (P0421) and I had it changed. A couple of weeks later the car started to sputter while in low idle and eventually I had to turn the engine off and start it back up to get rid of it. The check engine light turned back on, this time marking P0300 and P0421. I also noticed that while driving on the highway (60-70mph) the car would do a quick sputter and then it wouldn’t accelerate past 50mph. Again I had to come to complete stop and turn the engine off completely (at this time the car was sputtering on low idle) and turn it back on for it to go away and drive at a speed of about 55-60mph so it wouldn’t happen again. I took it to the mechanic again to check the catalyst converter again and if this was causing the random cylinder misfire as well. I just got off the phone with the mechanic and he says the problem seemed to be the oxygen sensor which they’ve changed and apparently all is well again. Does this make sense that an oxygen sensor triggers both P0421 and P0300? I will keep you posted once I drive the car for a while.
Reply With Quote
  #12  
Old 02-20-2009, 06:29 PM
Junior Member
 
Join Date: Feb 2009
Posts: 1
Default miss fire

well one thing that can cause the missfire ,is a very simple thing which a lot of shops overlook is the air hose from the mass airflow sensor to the intake manifold. it usually cracks at the fexible bellows and allows air into the circuit,,, most times it is this it is about 2 and five eights inches diameter put a new one on,,
hope this solves ypur problem
Reply With Quote
  #13  
Old 11-28-2017, 09:43 PM
Junior Member
 
Join Date: Nov 2017
Location: Louisiana
Posts: 1
Default P0300

Quote:
Originally Posted by luisovt View Post
I have a '02 Mazda Protege 5 with a similar problem (diagnostic code P0300 and P0421). Originally I had a problem with the catalyst converter (P0421) and I had it changed. A couple of weeks later the car started to sputter while in low idle and eventually I had to turn the engine off and start it back up to get rid of it. The check engine light turned back on, this time marking P0300 and P0421. I also noticed that while driving on the highway (60-70mph) the car would do a quick sputter and then it wouldn t accelerate past 50mph. Again I had to come to complete stop and turn the engine off completely (at this time the car was sputtering on low idle) and turn it back on for it to go away and drive at a speed of about 55-60mph so it wouldn t happen again. I took it to the mechanic again to check the catalyst converter again and if this was causing the random cylinder misfire as well. I just got off the phone with the mechanic and he says the problem seemed to be the oxygen sensor which they ve changed and apparently all is well again. Does this make sense that an oxygen sensor triggers both P0421 and P0300? I will keep you posted once I drive the car for a while.
I realize it has been several years since your original reply but my sons 02 is doing everything you described yours was doing. What you described your mechanic doing did it fix the problem with your car that you can remember? Thank you for your time.
Reply With Quote
  #14  
Old 02-12-2018, 06:57 AM
Junior Member
 
Join Date: Feb 2018
Location: casablanca
Posts: 7
Default

thanks for responding.
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
HELP! Code P0300 Millenia 2001 2.5L smithp3834 Mazda Millenia 0 09-22-2008 03:31 PM
CODE P0300 iamamicrowaveguy Mazda Millenia 2 12-09-2007 08:31 PM
P0300 Cjeck Engine Code YELLOW2001MP3 Mazda Protege 4 11-26-2007 07:30 PM
Code P0300 and P1195 vikas21 Mazda Protege 0 08-07-2007 12:12 PM
Help with code P0300 and P0420 buldozr Mazda Miata (MX-5) 2 01-19-2007 12:21 AM


Tags
2001, blocked, cat, check, code, codes, egr, engine, light, mazda, millenia, mpv, p0300, passage, plugged, po300

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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertising
Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 08:23 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.