I have an 08 legacy 2.5 that keeps bringing up the cel for p301&p302 at 5k and higher.

I have changed the plugs, coil pack and changed wires around to try to replicate problem on other cylinders to no avail.

I have had it to a garage who has monitored all sensors and parameters and everything is in spec other than it showing the miss fire on 1 and 2. I watched the tests being done on dealer grade scanners so I know they did check them.

Car runs fine. Gets around 22.5 to 23.5 mpg. I bought this car with deer damage so other than seeing some maintenance things being done in the past I dont know any history on the car.

I'm hoping someone can help me out!

1 & 2 or 1 & 3 ?

1&2 would seem to point to the coil....but, it's been changed

when was the timing belt last serviced?

has the car's oil been serviced regularly? decent brand oil filter?

odd

Edited October 23, 20187 yr by 1 Lucky Texan

Probably noise in the cam position sensor. Unfortunately that's a real tough one to diagnose over the internets. 

GD

 

6 hours ago, 1 Lucky Texan said:

1 & 2 or 1 & 3 ?

1&2 would seem to point to the coil....but, it's been changed

when was the timing belt last serviced?

has the car's oil been serviced regularly? decent brand oil filter?

odd

have no idea when the timing belt was last serviced unfortunately.

Oil was just changed when I did the plugs and I think I put a napa filter on it.

There is one other thing we noticed during diagnostics. The battery discharges rather quickly. Usually losing 4 volts in about 15 to 20 minutes. Battery tests okay but I dont think it should discharge that fast.

have the battery tested?

use an ammeter to check for 'dark current' - if it's high, pull fuses to find the system causing it. Might be a stuck CD in the head unit or bad wires in the hatch boot or ???

interference engine and you probably have original timingbelt - books says 105 months or 105K miles so, it's due. you WANT all japanese parts and to do rollers and tensioner with the belt.

Edited October 23, 20187 yr by 1 Lucky Texan

Definitely due for timing belt. It's 105k or 10 years whichever comes first. Doubt that's the cause of the misfire coding though. Probably has oil leaking head gaskets too. Par for the course.

GD

Believe it or not the car doesn't leak oil other than the power steering rack leaking. I had to change the valve cover gaskets and spark plug tube gaskets though. Engine has had work done to it. You can tell by some bolts being marked up, grounds from head aren't straps they are just copper wire, manifold or y pipe whatever it would be called on a subaru was changed. it almost looks as the engine was changed at some point due to some harnesses not being it brackets and such.

How do I go about checking the timing belt. I am not very familiar with these cars its the first Subaru I have ever owned so I don't know much about working on them.