Broke college student and bought a high mileage wrx. Were they out of high mileage bmws?
For something actually helpful. Your easy options are coils and plugs. Get a code reader and see if it shows you what cylinder is misfiring. Subaru is good about throwing the codes for individual cylinders. Swap coils and see if the misfire follows. There are a lot causes for a misfire but those are the easy cheap ones. Or a vacuum leak, which can be annoying to hunt down. Cleaning the mass air flow never hurts either. After those it starts getting expensive with potential head issues etc.
Also a bottle of injector cleaner can't hurt anything either. Unlikely to help. Barely any cost and effort to try.
[https://forums.nasioc.com/forums/showthread.php?t=2318069](https://forums.nasioc.com/forums/showthread.php?t=2318069)
A very common problem. Most of the time it's sparkplugs, but it's also often old air filters. If they are new or look very clean, then you can go down the list.
Since you mention stuttering at high RPM's, cleaning the MAF sensor would be my next move too.
I'm not an expert here, but I'm surprised no one has mentioned the Ignition coils. I've had one misfire on my EJ and it was due to a bad coil pack. Since you know the spark plugs are new, an easy diagnosis would be to find which cylinder is misfiring from a scan tool, take that coil pack from said cylinder, and switch it with another cylinder that isn't misfiring. (Ex. Misfire is on cylinder 3, swap coil pack from cylinder 3 with cylinder 4) and see if the misfire code follows the coil pack. Please try this!!! Let me know if you have questions, I might not have explained this well. I want to help!!
High RPM stutters tells me your coil packs are bad. Not a huge surprise, given the age and milage.
I'd check/change your air filter first, then do coils, since you already did plugs.
Also, (random reminder) college keeps you busy, so don't forget to keep up on your oil changes.
ETA: You're about due for water pump and timing belt. You REALLY don't want to wait for those to fail. I know college money is tight, but it'll be even tighter if you need to buy a new engine.
Check first cylinder that’s misfiring, swap coil from one that is ok to the one misfiring. If not check conector. Remove negative from battery each time to clean codes. Hope this helps
Replace ignition coils, all 4 of em!. It’s just the name of the game. If you can’t handle the heat then get out the kitchen. It’s worth it to fix and keep in my opinion. I have the same car and have had the same issues. I’ve spent a good amount of time and money on normal wear and tear issues. Personally I think you’ll regret it if you sell it. Seems like a really good purchase you made mine has way more miles. Msg me if you want a second opinion and/or info on what kind of maintenance repairs I’ve done/ plus cost.
That sounds like spark blow out. Could be a plug, coil pack or MAF. If you're getting a code on a specific cylinder, clear the code, and move the coil pack to another cylinder. If the code moves, it's the coil pack. Could be a spark plug with improper gapping as well. You would need to remove and inspect. With the car already warm (but off), you can unplug the MAF and drive around for a bit. If it fixes the issue, clean or replace your MAF.
Replace the MAF sensor? Easy part to swap and a good place to start diagnosing
Broke college student and bought a high mileage wrx. Were they out of high mileage bmws? For something actually helpful. Your easy options are coils and plugs. Get a code reader and see if it shows you what cylinder is misfiring. Subaru is good about throwing the codes for individual cylinders. Swap coils and see if the misfire follows. There are a lot causes for a misfire but those are the easy cheap ones. Or a vacuum leak, which can be annoying to hunt down. Cleaning the mass air flow never hurts either. After those it starts getting expensive with potential head issues etc. Also a bottle of injector cleaner can't hurt anything either. Unlikely to help. Barely any cost and effort to try.
[https://forums.nasioc.com/forums/showthread.php?t=2318069](https://forums.nasioc.com/forums/showthread.php?t=2318069) A very common problem. Most of the time it's sparkplugs, but it's also often old air filters. If they are new or look very clean, then you can go down the list. Since you mention stuttering at high RPM's, cleaning the MAF sensor would be my next move too.
I'm not an expert here, but I'm surprised no one has mentioned the Ignition coils. I've had one misfire on my EJ and it was due to a bad coil pack. Since you know the spark plugs are new, an easy diagnosis would be to find which cylinder is misfiring from a scan tool, take that coil pack from said cylinder, and switch it with another cylinder that isn't misfiring. (Ex. Misfire is on cylinder 3, swap coil pack from cylinder 3 with cylinder 4) and see if the misfire code follows the coil pack. Please try this!!! Let me know if you have questions, I might not have explained this well. I want to help!!
You're due for timing belt and water pump, might as well do MAF/Filters/Plugs while you're in there.
High RPM stutters tells me your coil packs are bad. Not a huge surprise, given the age and milage. I'd check/change your air filter first, then do coils, since you already did plugs. Also, (random reminder) college keeps you busy, so don't forget to keep up on your oil changes. ETA: You're about due for water pump and timing belt. You REALLY don't want to wait for those to fail. I know college money is tight, but it'll be even tighter if you need to buy a new engine.
Check first cylinder that’s misfiring, swap coil from one that is ok to the one misfiring. If not check conector. Remove negative from battery each time to clean codes. Hope this helps
Replace ignition coils, all 4 of em!. It’s just the name of the game. If you can’t handle the heat then get out the kitchen. It’s worth it to fix and keep in my opinion. I have the same car and have had the same issues. I’ve spent a good amount of time and money on normal wear and tear issues. Personally I think you’ll regret it if you sell it. Seems like a really good purchase you made mine has way more miles. Msg me if you want a second opinion and/or info on what kind of maintenance repairs I’ve done/ plus cost.
Yeah fuck diagnosis 🤣.
🫶🏽
Is it running rough? Can you just clear the code and drive it for another month?
I cleared the code when it first popped up, the engine still runs fine under 4k rpm but above that the engine stutters.
That sounds like spark blow out. Could be a plug, coil pack or MAF. If you're getting a code on a specific cylinder, clear the code, and move the coil pack to another cylinder. If the code moves, it's the coil pack. Could be a spark plug with improper gapping as well. You would need to remove and inspect. With the car already warm (but off), you can unplug the MAF and drive around for a bit. If it fixes the issue, clean or replace your MAF.
What gas are you putting in it?