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 Greg A Your Own Question
Greg A
Greg A , Master Troubleshooter
Category: Chevy
Satisfied Customers: 7808
Experience:  Working with Electronics & Cars for 25+ Years
Type Your Chevy Question Here...
Greg A is online now
A new question is answered every 9 seconds

My 2002 chevy Tracker 2.5l 6cyl automatic chugs when I ...

Resolved Question:

My 2002 chevy Tracker 2.5l 6cyl automatic chugs when I drive, but only after it goes about 8 miles, less sometimes. I thought it was a fuel filter, changed that, but no difference. I''ve had a SES light on for quite a while and it was Scanned and said it was an EVap code.Mechanics said I wouldn''t notice any drivability problems, and i haven''t until now. Its been 5months since that light came on. Mechancics now say that its the Mass airflow sensor, but the dealer says I don''t have one. Mechanics show me its connected to the top of the airfilter.Syptoms are worse for driving when going up hill. When I drive uphill in reverse it runs fine. Weird, I know...It also smells putrid when its ''trying'' to go. It will go into overdrive when I stomp on the pedal, which I also did out of curiosity, so I am just stumped about this. It stalls at intersections (sometimes) and sometime when I slow down turning into a parking lot or some such scene. Anyway...HELP!
Submitted: 8 years ago.
Category: Chevy
Expert:  Greg A replied 8 years ago.

HiCustomer Thank you for asking your question on Just Answer.

Did you happen to write down the EXACT error code that is turning your light on?
It should be 1 letter and 4 numbers.

I did check on the MAF, and the manual says "The mass air flow (MAF) sensor is an integral part of the throttle body assembly and cannot be serviced separately."


Customer: replied 8 years ago.
I do now...there were two actually:
P0447 and P0445..evap vent solenoid: low voltage, and evap purge solenoid; high voltage. What definative troubleshooting can be done to say that the MAF is what the problem is?
Thank you, XXXXX XXXXX
Expert:  Greg A replied 8 years ago.

Hi again.

I am not sure how the MAF became suspect, but the EVAP system will definitely cause problems if it is not functioning properly. Here are a few PDF files, that you should be able to view on your computer and print. These will describe the system and the two codes you gave me.

EVAP Description

Here is the main schematic that goes along with the error code testing procedures and a couple of diagrams that show where the main components of this system are.





What I would do is have that EVAP system checked and fixed. Again, if it is not working correctly, it could be causing the engine to not run properly, because the control systems will not be feeding the correct amount of fuel into the system at all times.

Once the EVAP system is functioning properly, the codes should be cleared and the system should perform better. Then if there are any remaining problems, they can be addressed.

I hope this helps. Please let me know if you have more questions.

Take Care, Greg A.

Greg A, Master Troubleshooter
Category: Chevy
Satisfied Customers: 7808
Experience: Working with Electronics & Cars for 25+ Years
Greg A and 4 other Chevy Specialists are ready to help you

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... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...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 L Rochester NY
< Previous | Next >
  • 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 L Rochester 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!!!! Alex Los 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. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, 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. Esther Woodstock, 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. Robin Elkton, Maryland

Meet The Experts:

  • GM Tech (Cam)

    GM Tech (Cam)

    Chevy Technician

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
< Last | Next >
  • GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Chevy Technician

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
  • Tim's Auto Repair's Avatar

    Tim's Auto Repair


    Satisfied Customers:

    Have owned a repair shop for 25 yrs.
  • Gary's Avatar


    Chevy Technician

    Satisfied Customers:

    15 years GM master tech
  • Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    ASE Master Certification. GM World Class Certification
  • John's Avatar


    Master A.S.E Automotive technician

    Satisfied Customers:

    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • Don 'Mo Lurch''s Avatar

    Don 'Mo Lurch'

    Auto Mech / Electronics

    Satisfied Customers:

    Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.
  • Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    18+yrs experience. State Inspector and Chevy Diagnostics

Related Chevy Questions