Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Chevy

I got the 303 error code on a Silverado 08 5.3 I have

Customer Question
I got the 303 error...
I got the 303 error code on a Silverado 08 5.3
I have replaced the following:
Spark plugs
Spark plug ignition wires
Checked all coils and all are good
Changed fuel pumps twice
Cleaned air mass flow
Still continue to have the code pop up and stability track light
Once you clear the code it runs good until it resets and the check engine light comes on again and it's runs shaky in low rpm.
What else I'm I missing?
Supposedly the dealer told me that I'm looking at a cam problem or something withing that severe of an issue.
Any suggestions?
Submitted: 1 year ago.Category: Chevy
Show More
Show Less
Ask Your Own Chevy Question
Answered in 6 minutes by:
8/25/2016
Chevy Mechanic: Master Auto Tech., A.S.E. Certified Master Technician replied 1 year ago
Master Auto Tech.
Master Auto Tech., A.S.E. Certified Master Technician
Category: Chevy
Satisfied Customers: 612
Experience: Over 20 years working on imports and domestic cars
Verified
I'm sorry you are having problems with your vehicle. I will try to help.I'm a full time mechanic and have been a mechanic for over 20 yrs and I work part-time here on JustAnswer to help you and others repair their own vehicles, and I get credited by your ratings.. So before leaving the site make sure and leave me a rating. You can still reply to me as many times as neeed, even after the rating.. I will need for you to be my hands and eyes since I'm not there.So when it sets the code it's going to kill the injector so you don't ruin the cat. That's why it runs worse when it sets the code.
That being said have you done a compression test on that entire bank? And have you tried swapping injector 3 and coil 3 with another cyl to see if the miss follows?I strive to provide 5 star service. If I have satisfactorily answered your question please rate it as such and hit submit. Doing so is the only way I get compensated for my time. Also it doesn't close the discussion so we will still be able to communicate if there are further questions.
Thanks
Sonny
Ask Your Own Chevy Question
Customer reply replied 1 year ago
Thank you for your response. I forgot to mention that I have done a compression test on all and all are good compression. I did swap coil 3 with another cylinder coil, erased the code and it came back with same code. Swapped again to a different cylinder coil to recheck, erased the code and came back with same code. I know that the coil is good. As a matter of fact I went bought a new coil threw it in cylinder 3 erased the code and still came back with the same code. Let me also add that I have checked for air leaks and have none.
Chevy Mechanic: Master Auto Tech., A.S.E. Certified Master Technician replied 1 year ago
it's possible you have a lifter problem, cam problem or injector problem.
I would swap injectors to rule it out. If it comes back #3 then it's either a lifter or cam. But IF it comes back I'd bet lifter. I've done lots of lifters in this year range.
Ask Your Own Chevy Question
Customer reply replied 1 year ago
My mechanic keeps telling me that it's the fuel pump. He swears that he's had the same problem multiple times and it ends up being a fuel pump problem. Also, isn't there a liquid I can add to engine that refills lifters?
Chevy Mechanic: Master Auto Tech., A.S.E. Certified Master Technician replied 1 year ago
I doubt that it's the pump. If the pressure is in spec then it's fine. Besides, I've never heard of a pump causing cyl 3 miss fire. Random miss fire yes. But not cyl specific.
And I don't know of any liquid per say. But if there was I wouldn't trust it to work. If it did it would be a temporary fix at best.
Ask Your Own Chevy Question
Customer reply replied 1 year ago
I will do the swaps and keep you posted. Thank you
Chevy Mechanic: Master Auto Tech., A.S.E. Certified Master Technician replied 1 year ago
Sounds good. Thanks
Ask Your Own Chevy Question
Chevy Mechanic: Master Auto Tech., A.S.E. Certified Master Technician replied 1 year ago
I strive to provide 5 star service. If I have satisfactorily answered your question please rate it as such and hit submit. Doing so is the only way I get compensated for my time. Also it doesn't close the discussion so we will still be able to communicate if there are further questions.
Thanks
Sonny
Ask Your Own Chevy Question
Ask Master Auto Tech. Your Own Question
Master Auto Tech.
Master Auto Tech.
Master Auto Tech., A.S.E. Certified Master Technician
Category: Chevy
Satisfied Customers: 612
612 Satisfied Customers
Experience: Over 20 years working on imports and domestic cars

Master Auto Tech. is online now

A new question is answered every 9 seconds

How JustAnswer works:

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

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 having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money.

Todd LRochester NY

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Chevy Technician

15,289 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,357 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,866 satisfied customers

Have owned a repair shop for 25 yrs.

Dave Nova

Dave Nova

Chevrolet Technician

7,092 satisfied customers

ASE Master Certification. GM World Class Certification

John

John

Master A.S.E Automotive technician

4,071 satisfied customers

A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician

Don - Mo Lurch

Don - Mo Lurch

Auto Mech / Electronics

2,918 satisfied customers

Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

Ron Z.

Ron Z.

- Chevy Tech -

2,734 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
I already change the spark plugs and wires on a Malibu 2003
I already change the spark plugs and wires on a Malibu 2003 Chevy it won't start … read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
Won't start, get spark from the spark plugs, have put gas in
won't start, get spark from the spark plugs, have put gas in the intact still won't start. Starter is turning all the belts … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
2014 Chevy Silverado 4.3 cylinder two misfire a spark plug
2014 Chevy Silverado 4.3 cylinder two misfire a spark plug is looks like it's wet with gasolineAlso engine code P0106… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
Pulled spark plug out and fuel came out with the plug.
pulled spark plug out and fuel came out with the plug. … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Misfire code p0306 I️ changer distributor cap spark plug and
Misfire code p0306 I️ changer distributor cap spark plug and wires new fuel pump don't understand why code is appearing … read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
58 satisfied customers
Misfire in cylinder #1 replaced coil and spark plugs, engine
misfire in cylinder #1 replaced coil and spark plugs, engine light on and flashing. Put in injector cleaner also. … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
Crank ok but won't start when hot, fuel 55psi,spark plug
when it cold start up no problem,i even replace coolant temp sensor… read more
Michael Solis
Michael Solis
363 satisfied customers
1 cylinder Spark Plugs crack and misfire. Random at first
1 cylinder Spark Plugs crack and misfire JA: How many miles are on the car? Is it a steady misfire? Or random? Customer: Random at first 79000 mjiles JA: What is the model/year of your Chevy? Customer… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Crank, no start. fuel pump is working. spark plugs (I think)
crank, no start. fuel pump is working. spark plugs (I think) are firing. … read more
eric remington
eric remington
FORMER SHOP OWNER/TECHNICIAN/INSPECTOR
associates degree
293 satisfied customers
I'm trying to change the spark-plugs on my 2006 chevy
Hi,I'm trying to change the spark-plugs on my 2006 chevy Malibu,3.5 But I ran into a problem,a couple of the spark-plugs seem to be froze.they don't turn one bit.how can I get them out with out Breaki… read more
Eric
Eric
Auto Technician
589 satisfied customers
Second opinion] I'm trying to change the spark-plugs on my
Second opinion] Hi,I'm trying to change the spark-plugs on my 2006 chevy Malibu,3.5 But I ran into a problem,a couple of the spark-plugs seem to be froze.they don't turn one bit.how can I get them out… read more
Jerry Newton
Jerry Newton
Vocational, Technical or Trade Scho
2,066 satisfied customers
P0300 and P0480, 09 Chevy cobalt, Coil pack, spark plugs,
P0300 and P0480 JA: What is the model/year of your Chevy? Customer: 09 Chevy cobalt JA: Are you fixing your Cobalt yourself? What have you tried so far? Customer: Coil pack, spark plugs JA: How many m… read more
roy
roy
Associate Degree
3 satisfied customers
Changed spark plugs wires coil on 2002 chevy s10 4.3 v6. no
changed spark plugs wires coil on 2002 chevy s10 4.3 v6 . no spark to engine ? … read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
Hard starting. 1996 S10 4.3 vortec. New spark plugs, wires,
Yes.... New spark plugs, wires, distributor cap and rotor … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
Want to replace spark plugs 2012 chevy Malibu 2.4 ltr but
Want to replace spark plugs 2012 chevy Malibu 2.4 ltr but plastic cover over entire engine bay has me concerned how do I remove this cover to access plugs? … read more
Ron Z.
Ron Z.
- Chevy Tech -
Vocational, Technical or Trade Scho
2,734 satisfied customers
No spark to my spark plugs, its a 1986, not sure exactly how
its a 1986, not sure exactly how many miles .... there is no spark to the plugs … read more
Jaybird61
Jaybird61
Master Automotive Mechanic
2,227 satisfied customers
The check engine is on. I have changed all the spark plugs
Hi the check engine is on. I have changed all the spark plugs and core and ignition core. … read more
GM Tech (Cam)
GM Tech (Cam)
Chevy Technician
Vocational, Technical or Trade Scho
15,289 satisfied customers
2009 spark plugs wet engine run rough loss of power. 41k
2009 spark plugs wet engine run rough loss of power. … read more
GM Bob
GM Bob
Automobile Technician
High School or GED
1,002 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x