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 rpmdiag Your Own Question
rpmdiag, Tech and Instructor
Category: Car
Satisfied Customers: 8144
Experience:  Since 1975
Type Your Car Question Here...
rpmdiag is online now
A new question is answered every 9 seconds

Its losing power when accelerating. Bogging down in a sense.

Customer Question

its losing power when accelerating. Bogging down in a sense. I had a diagnostic performed and it was a P0420 code. It's a CL fuel system with the fuel sys 2 NA. Does this sound like an 02 sensor or does it sound more like a fuel problems. I know that the 02 sensor regulates the fuel. It's STFT B1 is 0.0 and the LTFT B1 is 2.3?
JA: Are you certain it's the fuel pressure sensor that's in need of attention? What about the fuel rail? Have you checked it yet?
Customer: I dont see the valve to check it. I need to have another look.
JA: What is the make/model of your car?
Customer: 2008 Kia Spectra 5
JA: Are you fixing your Spectra yourself? What have you tried so far?
Customer: Yes I am. I have just been researching and a friend loaned me the diagnostics tool.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Other than I just bought the vehicle a week ago and all seemed fine. Had a 111,000 miles on it. There is also a squeal but I believe it is the power steering pump so I bought some Lucas power steering and some belt dress and it appears to have gotten better.
Submitted: 1 month ago.
Category: Car
Expert:  rpmdiag replied 1 month ago.

Hi, I'm Ron and I will be helping you today.
Stand by for a moment while I prepare your answer.

Expert:  rpmdiag replied 1 month ago.

Neither that code or an O2 sensor will cause that symptom, but you should check the MAF sensor with a scope or try cleaning it with MAF cleaner. Also check the fuel pressure and volume with a gauge.

Please understand that I don't know your skill level or tools
you have to assist us. Also understand that I can't see, smell,
hear, or touch the vehicle either, so your patience is
appreciated. JA is a great Q/A site, but it does not replace a
repair shop. So please don’t shoot the messenger if I have to
deliver bad news:)
If you are satisfied with my answer, I would greatly
appreciate a 5 star rating now before you leave the site and I
will still assist you after you have rated me too if another
question pops up. I don’t get credit for helping you until
you rate me

Thanks, Ron

Expert:  rpmdiag replied 1 month ago.

Did you have any more questions for me at this time?

Thanks again, Ron

Expert:  rpmdiag replied 1 month ago.

Thanks again and please remember to rate me 5 stars now
and keep this link in case you need me again later on.
I don’t get credit for assisting you until you rate me
My goal is to assist you in the repair of your vehicle by
supplying you with well educated information. I may not
always have the exact fix you wanted to hear, but my job is
to get you on the right track, which I always do. I can’t hear,
see, smell or touch your vehicle from where I’m at, so your
understanding of that is greatly appreciated. There are no
magical answers, but I do my best to guide you in the right