Subaru

Have Subaru questions? Ask a Subaru mechanic and get answers ASAP

Ask an Expert,
Get an Answer ASAP!

This answer was rated:

I have an 07 Foerster 2.5 non turbo that threw a p0402 code…

I have an 07 Foerster...
I have an 07 Foerster 2.5 non turbo that threw a p0402 code about 3 weeks ago. Been driving fine until the other day on the highway, I went to accelerate to pass and the engine bogged down. It smells like it's running rich.
It runs fine idling, even when I put it in drive foot on the brake and rev it up it holds rpm and runs fine. The minute I take it down the road and try to accelerate it bogs down has a deep growl (Like an after market highflow intake sound) and I can not give it more than 1/4 throttle. Anything more than 1/4 it starts to big.
I have checked all fluids
Changed 02 sensors up/down stream
Changed Cat (full front exhaust)
Changed plugs, wires, coil pack, and maf.
I'm stuck?
Show More
Show Less
Ask Your Own Subaru Question
Answered in 1 hour by:
11/19/2017
Matt
Matt, Engineer
Category: Subaru
Satisfied Customers: 23,083
Experience: Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
Verified

Hello

to get that code then its pointing to excessive EGR flow, which would also explain the loss of power

there are several possible reasons

the last is the most likely so I'd suggest to pull the EGR valve off and clean it out

  • The EGR valve is opening all the way or more than needed due to a blocked vacuum diaphragm in the EGR vacuum back pressure valve.

  • The EGR temperature sensor is registering too much of a temperature change when the EGR valve is opened from a partly blocked exhaust catalyst causing excessive back pressure in the EGR system.

  • The EGR is stuck open due to binding or carbon deposits holding the valve open.

Ask Your Own Subaru Question
Customer reply replied 6 months ago
Sorry for the delayed response work has been very busy. I just put a new egr valve on still have the same problem.

Hello

OK in that case I'd say to try fitting a thin blanking plate between the EGR valve and the inlet manifold with a tiny 3mm hole in the middle so there's a fraction of the EGR flow if this then helps and the valve is free moving then you know the issue is an electrical one so checking over the EGR valve wiring loom and connector would be the next step. or you may choose to just leave the blanking plate in there of course

Ask Your Own Subaru Question

Hi
do you still need help?
Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! If you're not pleased, also let me know because rating bad does not result in a refund, there are better options. Rating now will not close this post nor prevent further replies
Thanks Matt

Matt
Matt, Engineer
Category: Subaru
Satisfied Customers: 23,083
Experience: Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
Verified
Matt and 87 other Subaru Specialists are ready to help you
Ask your own question now
Was this answer helpful?
Ask Matt Your Own Question
Matt
Matt
Matt, Engineer
Category: Subaru
Satisfied Customers: 23,083
23,083 Satisfied Customers
Experience: Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing

Matt 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 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 PElm 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.

PhilMarysville, 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.

CharlesWalnut 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!

SueCharleston, 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.

JimCastleberry, FL

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

< Previous | Next >

Meet the Experts:

Kevin C.

Kevin C.

Subaru Master Tech.

1,727 satisfied customers

34 years of Subaru service experience, ASE Master Technician.

George H.

George H.

Subaru Certified Technician

1,330 satisfied customers

ASE Master Tech 15 + Years

Tim Mohr

Tim Mohr

ASE MASTER TECH

409 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Matt

Matt

Engineer

23,083 satisfied customers

Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing

Chris(aka-Moose)

Chris(aka-Moose)

Subaru Technician

289 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- Subaru Tech -

239 satisfied customers

18+yrs experience. State Inspector and Subaru Diagnostics

Don - Mo Lurch

Don - Mo Lurch

Subaru Mechanic

190 satisfied customers

Heavy Line Mech, Race Shop Owner, Mobile Electronics.

< Previous | Next >

Related Subaru Questions
Need to R&R nav system display. Just need how to break into
need to R&R nav system display JA: Okay, I'll connect you to the mechanic to go over that information regarding your Subaru. Before I do, is there anything else you want him to know? Customer: just ne… read more
tamaz22
tamaz22
60 satisfied customers
Subaru outback security light keeps blinking and won't let
Subaru outback security light keeps blinking and won't let my wife start our car. … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
Alot...lol. 2002 forester. And AIC valve, coil pack, new
yes and AIC valve, coil pack, new gastak, new pressure control solenoid valve, new fuel pump, new fuel control valve, cat converter … read more
tamaz22
tamaz22
60 satisfied customers
I have a 2003 subaru impreza that i bought. car was running
i have a 2003 subaru impreza that i bought. car was running when i purchased it from this kid. then the engine started knocking. cuz the other owner raced it must have blown the engine. so i replaced … read more
Matt
Matt
Engineer
23,083 satisfied customers
Had a check engine CPs sensor light. Drove for a while and
Drove for a while and it would come and go... some times on sometimes not. All the typical CPS issues … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I am about to buy a 2018 Subaru Crosstrek and I need to
I am about to buy a 2018 Subaru Crosstrek and I need to know: … read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
2005 subaru forester. I am trying to determine the load
2005 subaru forester. I am trying to determine the load grinding metallic sound coming from my engine. Be advised, have checked all fluides, good car is maintained well, and cant seem to isolate the n… read more
tamaz22
tamaz22
60 satisfied customers
I replaced a 2003 subaru impreza 2.5 engine. I've replaced a
i replaced a 2003 subaru impreza 2.5 engine. I've replaced a subaru engine before and had no problem. it started right away. but this 2003 is just cranking but won't start. so i changed the injectors,… read more
Chris(aka-Moose)
Chris(aka-Moose)
Subaru Technician
Vocational, Technical or Trade School
289 satisfied customers
Have 2 Crosstreks: 2017 & 2018. When towing up a steep
Have 2 Crosstreks: 2017 & 2018. When towing up a long steep grade, I sometimes smell a slight hydraulic fluid burning smell. Both have CVT's with a block-mounted heat exchanger circulating engine cool… read more
eric remington
eric remington
FORMER SHOP OWNER/TECHNICIAN/INSPECTOR
associates degree
575 satisfied customers
My brake & AT Oil Temp lights started flashing and the ABS
My brake & AT Oil Temp lights started flashing and the ABS light is on. I replaced the battery & brake pads 4 months ago, so that shouldn't be the problem. … read more
tamaz22
tamaz22
60 satisfied customers
My 2012 Subaru Outback instrument panel has a steady Engine
My 2012 Subaru Outback instrument panel has a steady Engine light illuminated, the VDC light illuminated, the TP light illuminated (Does ever shut off, yet the tire pressures are OK), the cruise contr… read more
tamaz22
tamaz22
60 satisfied customers
1996 subaru legacy 2.2l new fuel pump runs when cold but
1996 subaru legacy 2.2l new fuel pump runs when cold but after a while loses power when u push down on the accelerator but when u let off it will idle and run then when u push down again it will stall… read more
Matt
Matt
Engineer
23,083 satisfied customers
Leaking on the roof at the by the front windshield on both
Leaking on the roof at the by the front windshield on both sides … read more
Eric
Eric
Auto Technician
589 satisfied customers
Check Engine Light diagnostic P0030 Bank 1 Sensor 1. Where
Check Engine Light diagnostic P0030 Bank 1 Sensor 1. Where is this located … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
If I replace the tcm does it need to be programmed? 2013
if I replace the tcm does it need to be programmed? … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
2001 outback 2.5L engine, hesitates randomly while driving,
2001 outback 2.5L engine, hesitates randomly while driving, particularly when staring in first gear from a full stop or a turning. I tried changing the fuel filter, fuel pump, coil pack, spark plugs. … read more
rpmdiag
rpmdiag
High school
7,590 satisfied customers
2010 Outback mysterious noise: There is a noise like a
2010 Outback mysterious noise: There is a noise like a squirrel cage running coming from inside the dash on the driver's side that we can hear while the engine is running and for a few seconds after t… read more
tamaz22
tamaz22
60 satisfied customers
My keyless entry remote broke on my 2006 Impreza, bought 2
My keyless entry remote broke on my 2006 Impreza, bought 2 replacements but the system won't accept programming via manual mode or by computer at the locksmith.… read more
tamaz22
tamaz22
60 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