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: 23,480
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 9 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: 23,480
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?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a subaru mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Matt Your Own Question
Matt
Matt
Matt, Engineer
Category: Subaru
Satisfied Customers: 23,480
23,480 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

1,349 satisfied customers

ASE Master Tech 15 + Years

Tim Mohr

Tim Mohr

ASE MASTER TECH

418 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Matt

Matt

Engineer

23,480 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

332 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- Subaru Tech -

260 satisfied customers

18+yrs experience. State Inspector and Subaru Diagnostics

Don - Mo Lurch

Don - Mo Lurch

Subaru Mechanic

193 satisfied customers

Heavy Line Mech, Race Shop Owner, Mobile Electronics.

< Previous | Next >

Related Subaru Questions
2007 Outback 2.5 P0171. Checked for leaks around intake
2007 Outback 2.5 P0171. Checked for leaks around intake w/carb cleaner manifold several times. Cleaned MAF sensor. Replaced PCV hose (really thought that was it). New front oxy sensor 16 months ago. J… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
P0172 98 impreza motor in an 03 forester, already serviced
p0172 98 impreza motor in an 03 forester , already serviced injectors , replaced fuel pressure regulator , replaced front 02 , no exhaust leaks , replaced intake air temp sensor , replaced tps , clean… read more
Shawn Few
Shawn Few
AS
135 satisfied customers
I have a 2007 outback with the 2.5 sohc engine. Im having a
I have a 2007 outback with the 2.5 sohc engine. Im having a severe lack of power and a stumble/hesitation. Its starts and runs just fine though. I checked the timing as well as put new plugs in and sp… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I have mystery flat spot on accel missing on 3 cylinder lt
i have mystery flat spot on accel missing on 3 cylinder lt fuel -25 o2 sensor .855 volts av running rich swapped out for none good injectors all plugs black but #3 has 160. comp misses all the way thr… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
Subaru Impreza 2.5I: I have a 2008 subaru impreza 2.5i. I was
I have a 2008 subaru impreza 2.5i. I was driving it the other day and did a hard acceleration and now it won't give over 20mph or rev over like 3000 rpm...seems to bog when I try to drive it like it d… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Subaru Legacy 2.5I: Hello. My legacy 2009 stayed in garage
Hello. My legacy 2009 stayed in garage for 6 months and after that it got a problem of slightly fluctuating rpms under load (going uphill) and i get p2097 code as well. not sure if those two are conne… read more
tamaz22
tamaz22
60 satisfied customers
I have a 1999 Subaru Legacy Outback 2.5 with 150,000 miles.
I have a 1999 Subaru Legacy Outback 2.5 with 150,000 miles. Recently had the head gaskets done, and shortly after (within 100 miles) got a Check Engine light which turned out to be P0304, Cylinder 4 m… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
Subaru Impreza Outback Sport: hello, I have a 99 subaru Impreza
hello, I have a 99 subaru Impreza with the 2.2l. The problem I am having is that it bogs down while accelerating. I have changed the front o2, maf. the car will run fine after resetting the ecu for ab… read more
tamaz22
tamaz22
60 satisfied customers
Subaru Impreza: I have a 1999 Subaru Impreza L, 2.2L. In colder
I have a 1999 Subaru Impreza L, 2.2L. In colder weather the engine idles at high Rpm's at start up; occasionally I'll get a check engine light, which shuts off after a few start cycles. I also have to… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
2007 Subaru Outback 2.5i: km..rev up the engine..ride..stalling
Two days ago I took my 2007 Subaru Outback 2.5i (92000 km) through some deep(ish) snow, maybe 8 inches, and got bogged down on an uphill. I was able to get out without much trouble but in doing so I h… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
2003 Legacy: 2.5 engine..problem with exceleration.
I have a 2003 Legacy, 2.5 engine. It has a problem with exceleration. Help! It bogs down when I take off from a stop. There are no codes on a computer. It runs good at highway speeds until I get to a … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
1998 Subaru: starts great, runs great..sputter..accelerate..gas tank
1998 Subaru, Legacy Outback, starts great, runs great when cold, idles down just fine (it is not trying to stall when car is braked to a stop)wants to sputter and stall when I try to accelerate from a… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
97 Impreza Outback: rich..Changed both cats and both o2 sensors.
97 Impreza Outback. Running very rich. Changed both cats and both O2 sensors. Spark plugs and wires changed. Fuel filter as well. Watched data stream. Before O2 sensor switching fine. Rear will only r… read more
Paul M ASE Master
Paul M ASE Master
Automotive College
3,307 satisfied customers
2004 Forester: squeak..15 mph..highway for 30 mins, the growling came
My 2004 Forester has had a chirpy squeak coming from the front pass. wheel for the last few weeks, mostly at 10-15 mph. Tonight, after driving on the highway for 30 mins, the growling came back for 1 … read more
George H.
George H.
Subaru Certified Technician
Associate Degree
1,349 satisfied customers
Per FIXITMANs recommendation on my previous JustAnswer” question,
Per FIXITMAN's recommendation on my previous “JustAnswer” question, I had a new catalytic converter(s) installed (it has 2). Please review previous question. This was also the recommendation of a prof… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
My car is very jerky as I accelerate. I have changed plugs
My car is very jerky as I accelerate. I have changed plugs and leads, fuel and air filters with no effect. THe engine light came on briefly while on the highway. It runs well on the highway except for… read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
01 Outback: Stumbles..acceleration..30 mpg and running fine otherwise
My '01 Outback Wagon Stumbles on acceleration from either standing start or when passing and climbing steep grades w/ A/C on. It Has had the 89,000 mile service done two years ago and now has 110,000 … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
93 Subaru impreza: low rpm bogs down and moves..reaches..smooth
Hello I have a 93 Subaru Impreza 1.8L. Drive ability problem. Inconsistently usually at low RPM bogs down and moves very slow, unitl it finally reaches about 2000~2200rpm then it will smooth out to no… read more
Pietros
Pietros
Advanced Motor Craft, Franchise tra
68 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