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 tamaz Your Own Question
tamaz, Subaru master technician
Category: Subaru
Satisfied Customers: 1278
Experience:  Subaru certified,ASE Master technician,25 years experience
Type Your Subaru Question Here...
tamaz is online now
A new question is answered every 9 seconds

Having fuel issues with 05 subi outback xt turbo

Customer Question

Having fuel issues with 05 subi outback xt turbo
Submitted: 1 year ago.
Category: Subaru
Customer: replied 1 year ago.
Engine was rebuilt @ 170k miles. Initially car had bad turbo. Replaced turbo during rebuild. Car would surge bad during acceleration. Replaced mass air flow sensor, upstream o2, and had a faulty knock sensor pulling tons of timing. In have a Cobb Accessport to guage a/f and log stuff but have little knowledge about what I'm staring at.
Customer: replied 1 year ago.
Replacememt knock sensor solved part of a problem but the car still surges slightly. While accelerating and watching a/f its constanltly changing up/down up/down up/down like it cant find the right ratio. And while I'm watching it try to trim I can feel the changes during near constant speed on the highway 2500-3000 rpm ish. It doesnt trim at all during idle. Could this be one of the other o2 sensors?
Customer: replied 1 year ago.
The access port shows tons of data i just dont know whats important to watch to narrow down this issue.
Expert:  tamaz replied 1 year ago.

Hi, did this problem start immediately after the rebuild? Has the cam timing been checked?

Customer: replied 1 year ago.
I do believe timing was checked by two different mechanics and they said it was right. Yes it was quite a bit more noticeable after the rebuild but after replacing the mass air flow sensor, the upstream o2 sensor, and the knock sensor it's not as bad as it used to be.
Customer: replied 1 year ago.
Possibly part of the variable valve timing system?
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  tamaz replied 1 year ago.

Hi,does the check engine lamp come on and did you remove the tune to see how it runs?