Have not got to the plugs yet but failing coil pack? I felt no loss in power light would blink once in awhile but not all the time.

Plugs, wires (especially if htey aren't OEM on a 2.5) and then coil pack is my order.

 

It's usually electrical when you get 2 opposing cylinder codes due to the wasted spark ignition system.

 

Please state year and engine.

1/2 and 3/4 misfires are often coil related.

Are you having the problem more when it's wet out? Or is it just random?

Its been damp and rainy since I got the car... Wires dont look oem and my 3 week old NGK wires only fit my ej22

 

Car is 97 outback

Edited April 20, 201114 yr by 1-3-2-4

Its been damp and rainy since I got the car... Wires dont look oem and my 3 week old NGK wires only fit my ej22

 

Give it the Chinese water torture... Take a spray bottle with water and spray it over the wires and see if you can get leaky spark and make it miss. Non-oem wires and plugs cause issues like this though. That will tell you if it's damp related. If it's not, it could be a failing coil, ignitor, low compression on those cylinders, sticking valve.... there's a lot that will cause a misfire.

I can try this when I get home I havent checked the vavles yet I do have a vac gauge to checl

1/2 or 3/4 is ELECTRICAL not mechanical. As in valves needing adjusting, etc.

 

Start witht he NGK 2 dollar plugs with the green writing BKR6E-11? or close. That'll give you a chance to check the wires better as well.

 

If you want a used coil let me know - I shoul dhave several, and some like new OEM wires too. But some years the coil pack was different where the wires plugged in. Some took male and some took female wires. And you can swap the coil and wires together to get them to match up.

 

IIR OEM wires are like 100 bucks. Coils - I have enough used ones I never needed to buy. But hte "Diamond" brand seems to be preferred.

I had the same problem about 6 months ago but kept ignoring it. Finally it got so bad that once I reset the codes it would come back within 40 miles.

 

I changed the knock sensor since it needed it anyway and then the plugs. The plugs that the manual call for are PFR5B-11 but they are 12 bucks a piece . I used BKR5EGP at 4 bucks a piece and they work good.

 

It turned out that the plugs were totally shot......

 

It has been 2000 miles and all seems to be good.

 

When troubleshooting, try the easier things first. If that fails, then go to the hard stuff.

Yeah I'm sure it's one or the other.. the past owners did not do so well in taking care of this car..

 

Funny thing is I don't feel a loss of power unlike the last time I had a misfire in the 98 Forester back in 2000.

 

This morning I was at 4K and I noticed the light blinking.. I'm going to go clear the code again but I'm going to also do the water spray test as well.

hmm the manual says PFR5B-11?

 

I'm looking at the service manual and it says this

 

RC10YC4 .......... CHAMPION

BKR6E-11 .......... NGK

K20PR-U11 .......... NIPPONDENSO

 

I'm not sure if it's the same as the owners manual but I'm not sure why it would say something different..

 

I think they are all copper plugs which is fine for me I guess no big deal.. Also no misfires this morning but it's been dry for the past 24 hours but I forgot to do the water mist last night but will do it tonight.

IIR the heat range is different.

 

And the 2.2's that the 5's

and the 2.5 take the 6's

because it would be too simple to remember if the 2.5's took the 5's.

 

You have another thread going. The knock sensor won't set the missfore code - it's set the knock sensor code.

 

Fix one thing at a time. I'd start with plugs, then wires, then coil myself.

 

When doing the plugs carefully inspect the wires.

 

Heck - you might even wanna swap the wires form 1 to 3 and 2 to 4 to see if the problem follows the wires and not the coil. I often do this when installing new plugs when starting to chase this problem.

yeah I know the knock sensor and the misfire are unrelated So i will start with the plugs I really can't remember what extensions and U joints I used for the drivers side plugs it's been 7 years.. I think a extension and a U-joint is enough to get the plugs out? I just remember it was a tight fit.

This has the DOHC, right?

You need a couple short extensions, u-joint helps a bit.

This has the DOHC, right?

You need a couple short extensions, u-joint helps a bit.

 

yep DOHC, I have a small and a med one and a long one

IIR the heat range is different.

 

And the 2.2's that the 5's

and the 2.5 take the 6's

because it would be too simple to remember if the 2.5's took the 5's.

 

 

I just checked my owners manual and it states the following:

 

2.2 - Champion RC10YC4, alternate - NGK BKR6E-11 or Nippon Denso K20PR-U11\

 

2.5 - NGK PFR5B-11

 

 

The heat range is shown by the part number of the plugs.

 

PFR5B-11 - 5 heat range

 

PFR6B-11 - 6 heat range

 

I double checked the NGK plug website when I bought my new plugs and they also recommend the 5 heat range.

Edited April 22, 201114 yr by doc526

I did the water test and no stray sparks so next is left is the plugs.. last time that I know that they were done is 66,000 as someone left all the work done on the car at a subaru dealership.

Got the plugs

 

 

NGK part # 7090 aka BKR5EGP

Edited April 22, 201114 yr by 1-3-2-4

When I do plugs in the DOHC I take my whole saw and just cut a hole through the tire, through the fender, through the frame, right to the engine head. Then just use a really long extension. Makes the plugs a breeze! Just be sure to avoid the AC lines.

Got the plugs

 

 

NGK part # 7090 aka BKR5EGP

 

I've had better luck with the less exotic plugs.

 

The 2 dollar ones with the green printing(not with the blue printing).

 

Infact on these late 90's I have seen platimuns cause problems - but often they were Bosch.

 

Best case you spent more than needed.

 

The mid 2000's start calling for "laser platinum" or "double platinum" plugs.

When I had my 98 Forester 2.5 same EJ25D when I changed the plugs and used platinum and Bosch I would get a misfire from them.. I later swapped them out for the correct kind (still platinum NGK) and it was fine until re traded the car in for an 03 FXS

 

I'm not sure if I'm going to get to the plugs today or not just because it's another trip to the auto store because I don't have a 3/8 U-joint

When I had my 98 Forester 2.5 same EJ25D when I changed the plugs and used platinum and Bosch I would get a misfire from them.. I later swapped them out for the correct kind (still platinum NGK) and it was fine until re traded the car in for an 03 FXS

 

I'm not sure if I'm going to get to the plugs today or not just because it's another trip to the auto store because I don't have a 3/8 U-joint

 

This is what happened when I (ignorantly) used Bosch platinum plugs

 

Ouch what happend?

Ouch what happend?

 

About 2000 miles after I put in those plugs it started running like crap. They all looked like that.

Wow that sucks big time

Wow that sucks big time

 

They're easy on a 2.2, but lesson learned.