p0303 p0304

[Jdubgt530]

Bought a 1997 Subaru Legacy Gt with 142,xxx miles on it this last week and as I was driving away I noticed that the check engine light was blinking. Immediately I stopped at the gas station and pulled out the code reader. P0303 and P0304. I automatically bought spark plugs (NGK Iridium .40 gap checked), Omnispark spark plug wires, and import direct coil pack. I installed all of the above into my GT and since I took the battery out I was unable to get a smog check for CA registration. I then drove to the DMV to check an operating permit so I can still drive it to work and home. On my way there the check engine light pulled up again, p0303 p0304. I cleared the code and when I was on my way back from the DMV it popped up again. So I did some testing and if I keep it below 50 it doesn't pull the code and start flashing the light at me (which I know is CAT damage). The car doesn't idle rough at all. It stays at 800 rpm's at idle and still has plenty of power in the engine. I haven't done a compression test on it to find out where my compression is at, when I do I will post my findings on here. Please help me diagnose this! I'm in complete awe on what it could be since the engine does run rough and the code doesn't pull till I hit 50 mph. If I keep it at 45 mph or lower, no code pulls up. Thanks!

[johnegg]

i'm not familiar with the brand names of the coil or the wires,

so i have no idea if they are high quality or not.

i probably would have stuck with ''subaru'' for both,

used coil and new suabru wires.

mostly, suabru parts are extremely high quality.

of course there are a few exceptions,

like forester wheel bearings in the late 90s

and ej25 rod bearings in the early 00s.

 

many used subaru parts are better quality and longer lasting than other brands, imho.

 

but assuming the new parts are working correctly,

(you did install them, right?)

then i would look at the igniter next.

it feeds the coil in the same front vs rear set up that the coli fires the plugs.

and sometimes coils get replaced when in fact the igniter is causing the issue.

 

it igniter is located on the fire wall, trans mount , dog bone,

center of the fire wall at the top,

near the hood.

look behind the air resonator box .

 

again a good used part could save some money and work well.

plus, is this is not the cause you have save a few $$

 

 

good luck.

[Jdubgt530]

I will check that out! Import direct I bought from O'reilly, and they are OEM parts. How much do you think the igniter would cost me?

[taylormac1993]

Been having the same issue for a while, meanwhile my idle and engine performance is slowly but surely deteriorating. I have chased this ghost for almost a year (on and off, had other projects) so if the ignitor thing works i will be ecstatic. Any other leads to follow if this isnt it for either of us?

[Jdubgt530]

Well I had my misfire diagnosed at a Subaru specialty shop in my town and they checked the ignition system and there are no problems there. Compression is great in it. They said that the cause of it could be the timing being slightly off and the crankshaft pulley might need replacing. They said that my GT is running great and that it isn't a true misfire. Waiting for my next check to buy a full Gates timing belt kit with the water pump. I changed out the crankshaft position sensor and camshaft position sensor and I'm still pulling the code. So last thing to do is do the timing on it and make sure everything is all dialed in. Hopefully that fixes it!

[johnegg]

the timing may be off,

probably is off,

but #3 and #4 are on different cams,

so it is unlikely that is the only problem.

 

but they are the pros and i'm not,

so i hope they fix it.

 

i still think it is coil/igniter related.

but i'm not an expert.

[taylormac1993]

Sorry if im hijacking your thread but now im throwing p1507 and p1722 in addition to the misfires. I also noticed that if i keep it below 45, my car doesnt die when i idle. Is your car auto or standard?

[Jdubgt530]

I am repairing it myself because I trust myself more then most shops in my town. I just brought it to them to see if they could narrow down what could be causing it. So I'm going to bust out the timing belt and components, and then if that doesn't fix it then replace all of the injectors. They said that none of the electronics with the ignition system is bad and that I did everything correctly.

 

Not a problem man that is what the forums are for. I have seen some videos on the web about the codes, check them out and see if you can narrow down what can be causing it. Lots of trial and error. I know this from these damn p0303 and p0304 codes. Specially since the car is running great. Idles fine and has a ton of power.

[taylormac1993]

Im just trying to see if those other codes are related to my tranny swap or not. Lol

[savage91b]

I have a ej22 and I have the same issue along with a evap emissions system code any help ? Manual transmission still has all power...n normal idle thanks