How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Mike O. Your Own Question

Mike O.
Mike O., Master Technician
Category: Nissan
Satisfied Customers: 397
Experience:  18 years with Nissan/Infiniti dealerships
39767275
Type Your Nissan Question Here...
Mike O. is online now
A new question is answered every 9 seconds

Nissan/Datsun Altima SE How do I get rid of a P0300 multiple

Customer Question

How do I get rid of a P0300 multiple misfire code?
Submitted: 4 years ago.
Category: Nissan
Expert:  Mike O. replied 4 years ago.

Mike O. :

Hi my name's XXXXX XXXXX for the question!

Mike O. :

Well it's highly unlikely that the cats are causing a misfire code, however a misfiring engine can cause damage to the cats so maybe that's where those shops are mistaken. There are a few common things on altimas that will cause that code. First, check the ground cable from the battery to the transmission. If it's frayed or broken, it will need to be replaced. The ignition coils will definitely cause a misfire especially if you see that the tops of the coils are blistered or melted. Also the injectors tend to go bad on altimas. You'll need a ohmeter to check the resistance across the injectors to see if they're ok or not.

Mike O. :

It is possible that all the injectors are bad or just one is bad and is affecting the bank of incident cylinders causing the multi-cylinder misfire so you'll need to check them all to be sure. If you have an ohmeter let me know and i'll tell you an easy way to check them. I would rule out the catalytic converters for now if I were you.

Customer:

I don't think everything got sent last night.



I have a 2005 Nissan Altima SE3.5. It is a rebuilt salvage that was hit on the right front. Airbags/front seatbelts dont work. I bought the car from a thrid party after it was wrecked and "fixed". When I bought the car in march it had been sitting for 3 years and had 31000 miles, now it has 41000. Since I have bought the car I've been trying to get rid of a multiple misfire that seems impossible as its been taken to 8 different shops. They all concluded it was the catalytic converters. The 2 in front were for some reason hollowed out. I replaced all 3. No change. I replaced all spark plugs, O2 sensors, air/fuel ratio sensor, plentum gasket, fuel system tune up, bought a new ecm, the dealer tried to install but car wouldnt start so switch back to the one that was in it. I finally had it towed to 80 miles to a guy that started at the variable induction control silenoid. He put a GM part on there just to see if it'd make a differnce before spending the money. He also unplugged an O2 sensor then drove it for about 15 minutes. Not sure how but the misfire was gone. A month and a half later my codes were pulled and cleared and the misfire came back immediatly . Ive tried to get rid of it and have spent too much money. Why did clearing the codes cause the code to come back? and how do I get rid of it for good? Please help. Ive tried to educate myself on this issue but it doesn't seem to be able to be pinpointed. Thank You in advance



JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was in trouble with an electrical issue with my brand new Nissan. I frantically went online trying to find help and luckily I found your site. I reached a NISSAN tech named RIP. He was absolutely tremendous and helped me work through the issue. What a pro! cjaz Lexington, KY
< Last | Next >
  • I was in trouble with an electrical issue with my brand new Nissan. I frantically went online trying to find help and luckily I found your site. I reached a NISSAN tech named RIP. He was absolutely tremendous and helped me work through the issue. What a pro! cjaz Lexington, KY
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim Castleberry, FL
 
 
 

Meet The Experts:

 
 
 
  • Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    446
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL
< Last | Next >
  • http://ww2.justanswer.com/uploads/tsmodie/2009-6-10_144056_tim.jpg Tim Mohr's Avatar

    Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    446
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL
  • http://ww2.justanswer.com/uploads/CA/caprio23/2011-12-13_155550_20111213105344.64x64.jpg Anthony's Avatar

    Anthony

    ASE Certified Technician

    Satisfied Customers:

    306
    ASE Master Automobile Technician with over 18 years exp. in this field.
  • http://ww2.justanswer.com/uploads/FO/fordguy4u/2011-12-17_222940_HPIM1257.64x64.JPG Ron's Avatar

    Ron

    ASE Certified Technician

    Satisfied Customers:

    171
    34 years of automotive Repair
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris(aka-Moose)'s Avatar

    Chris(aka-Moose)

    Nissan Technician

    Satisfied Customers:

    165
    16 years of experience
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    ASE Certified Technician

    Satisfied Customers:

    127
    ASE & Bosch master tech. 30 years experience.
  • http://ww2.justanswer.com/uploads/BA/baddad1/2013-8-30_131413_11848761610058140852271553042976n.64x64.jpg Mike V.'s Avatar

    Mike V.

    Nissan Technician

    Satisfied Customers:

    7443
    Nissan factory trained and Certified Subaru Technician.
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    92
    Nissan Tech ASE certified technician
 
 
 
Chat Now With A Nissan Mechanic
Mike O.
Mike O.
Automotive Technician
297 Satisfied Customers
18 years with Nissan/Infiniti dealerships