Subaru Forester misfire problems

Filed Aug 3, 2026 · Engine, Fuel system · MO

Engine is misfiring, causing in ability to accelerate properly and loads multiple error codes. Upon taking it to the dealership for services, we were told that there is a significant amount of carbon built-up inside the engine. The car has only 6,800 miles on it. The dealership stated that it is an issue that Subaru engineering is aware of but has yet to figure a way to resolve it. The dealership informed us that hybrid engines have had severe carbon build-up on the in-take valves that causes misfiring, loss of power, bucking and stumbling of the engine. Apparently this has been reported all over different on-line forums. The dealer informed us that they would need to order a valve cleaning kit as referenced un service bulletin 02-193-24 and the engine would require walnut blasting. The vehicle was dropped off for service on 7/22 the work was completed, but upon restarting the engine more codes fired up and they stated that the Electronic Communication Module failed and it would now require an escalation to the Subaru Engineers called TechLine, "they now say that the ECM now needs replacement, still misfiring and has become a more complicated issue"

Filed Jan 8, 2026 · Driver assistance, Engine · VA

Engine lost power and was misfiring while many warning symbols appeared on the dash. There was a divider separating the lanes. The car coasted to almost to a stop, but the engine chugged enough to slowly turn left at the first opening in the divider and just barely made it off the main road. The engine stopped. I restarted it several times. The engine was misfiring barely running. The electric brake was applied on its own. The car did not respond to moving the shift selector out of park, so the car was immobilized. I put the 4-way flashers on and called AAA. There seemed to be no way for me to move it out of park or release the electronic parking brake. AAA could not respond quickly and suggested I call the police to divert traffic around my car for safety which I did. The tow truck operator was able to disengage the wheels and was able to flatbed it to the nearest repair shop. This being Saturday 1/3/26 it wasn't until Tuesday the repair shop determined the car would not run long enough to provide a reliable diagnosis due to the multiple trouble codes coming up on the computer analysis. I had the car towed to the nearest Subaru dealership who replaced the thermos control valve under their warranty extension. The dealership said usually when this part fails it just triggers a check engine light and not the dangerous situation I experienced. I believe a recall to replace this part should be issued on all cars with this defective part as its failure can cause a dangerous situation without warning.

Filed Apr 23, 2025 · Engine · ME

Subaru Forrester was misfiring and sputtering as if it was going to stop running. The car was shaking. Had car towed to Subaru dealer for Service. At first we thought Spark Plugs and Ignition Coils but this did not fix the issue. Service determined a spring valve was broken which caused the issues. I have escalated the issue with Subaru Corporate, waiting for their response. Other Subaru models have had this issue with the spring valves.

Filed May 8, 2023 · TN

While driving on the highway my car started to stall and rough idle, It wouldn't drive past 2 rpm sometimes less and would stall. My car constantly stalling made multiple cars/semi-trucks almost hit me and cause them to swerve. The problem was confirmed to be the thermo control valve eroding, which Grayson of Subaru verified. The manufacturer inspected it and confirmed this needed replaced. The only warning signs or messages that appeared appeared after the vehicle stalled when the check engine light, and all lights on the dashboard lit up. Subaru of America has even admitted that this is a problem and offered to pay part of the cost to fix it, therefore knowing they are at fault. They have said they would email me/contact me but haven't returned any correspondence.

Filed Jan 21, 2023 · Electrical · FL

We took our 2017 Subaru Forester on December 9, 2022, to change the ignition switch because our key continued getting stuck. It was covered under an extended warranty. The spark plugs were changed during the same appointment only to satisfy the maintenance agreement. Before we took our Subaru in, our vehicle was running at an optimal level, and nothing was wrong with how it drove. On December 10, 2022, we drove our car, and it started to hesitate and misfire. This has never happened before. We called the dealership, and they had us bring the vehicle back in. They performed a fuel injection cleaning and reset the computer. Once again, the same problem continued after picking up our vehicle. The same problem continued daily, and several calls were made to the dealership and trips to the maintenance service department. It is erratic when it happens, but we have experienced it more during city driving versus highway driving. It’s been over a month, and the problem is still not resolved. At this point, we genuinely feel that this is a safety issue. Not to mention that if the vehicle continues to perform poorly, it can create additional damage. We are at a point of pure frustration and disappointment.

Filed Nov 1, 2022 · Transmission · CA

The other day, the check engine light came on & Eyesight was disabled. I take it to the nearest mechanic who tells me that the cooling fans are running too long at idle & this could drain the battery. He also tells me to watch for the engine overheating. The recently checked coolant level had dropped lower than the minimum. I take it to dealer who keeps it for day. Similar to the 2 other complaints, the fault is related to TSB-09-80-21R calling for replacement parts to be installed. Subaru did not do any recall but instead waited for the parts to fail. I have minimal heat & the engine runs cool a lot of the time which affects emissions. My gas mileage is getting worse. The part is on backorder with no estimated time of arrival. I was told to just keep driving it & to let them know if it starts to run rough. The dealer said there are a lot of other cars & drivers in this situation at the dealer’s service department.

Filed Dec 14, 2020 · Engine · 55,000 miles · CA

Vehicle stalled in intersection. Car has a rough idle, this is the second time it has stalled. Dealership has looked at the car but not resolved the issue.

Filed Oct 15, 2020 · Transmission · 120,000 miles · CA

Rough idling, uneven acceleration when stepped on gas, the car would accelerate, slow down, and accelerate again. Uneven deceleration when letting go of gas, the car would slow down, speed up, and slow down again. Seem like a software problem with computer.

Filed May 19, 2020 · Acceleration, Engine · 60,000 miles · MI

This is an intermittent problem. The vehicle surges sometimes and misfires when it cold starts. I took the car to the retailer, they did not found any issue. Only the differential oil was changed. They told me to return if the problem occurs again. Again it came back and intermittent. I am sure retailer will not be able to find the problem again. It is sudden loss of powers for couple seconds and it a hazard on the road. Hope there are recalls on this issue.

Filed Oct 28, 2019 · Engine · 54,000 miles · OR

While driving normal speeds, the car's check engine light came on. I scanned the code, the car is getting a p0016 code, and the car has a rough idle. The wilsonville subaru dealer has said that a new ECM and cam sprocket needs to be replaced in order for this issue to be fixed. The issue seems to be a factory defect with the cam sprocket, "coming apart" and causing the engine to lose timing. This seems to be a common issue people are having online with this engine as well. Anad, apparently the issue will come back if the ECM isn't replaced as the ECM "hard codes" the error in the computer and it wont go away unless replaced. Making the issue unresolvable outside of drivetrain warranty without subaru's assistance. Subaru is refusing to do the repairs.