Hello!
I have a modded STI that keeps throwing codes P000 and P0301 with P0303 and P0304 being intermittent.
It has 54k original miles. Within 5k miles the timing belt and water pump have been replaced (previous owner had a shop do it with receipts) when I purchased the vehicle it ran fine for about 50 miles, then started having issues. I took it in to my local Subaru dealer and had them do a compression/leak down test and it came back solid. They replaced the spark plugs and coil packs. It drove out fine but the problem came up again about 20 miles later. Low rpm major loss of power under pressure. As soon as it hits around 3k rpm it drives great on a base map. If I change it to a stage 1 91 tune the misfire hits at higher rpms. Hoping to get some answers in here before I visit another shop. Thanks!
I have a modded STI that keeps throwing codes P000 and P0301 with P0303 and P0304 being intermittent.
It has 54k original miles. Within 5k miles the timing belt and water pump have been replaced (previous owner had a shop do it with receipts) when I purchased the vehicle it ran fine for about 50 miles, then started having issues. I took it in to my local Subaru dealer and had them do a compression/leak down test and it came back solid. They replaced the spark plugs and coil packs. It drove out fine but the problem came up again about 20 miles later. Low rpm major loss of power under pressure. As soon as it hits around 3k rpm it drives great on a base map. If I change it to a stage 1 91 tune the misfire hits at higher rpms. Hoping to get some answers in here before I visit another shop. Thanks!