Is there no "check engine" light on? No error codes?

Is the fuel pressure regulator OK?

 

Is there no "check engine" light on? No error codes?

Is the fuel pressure regulator OK?

I forgot to say it, there is never a check engine light nor any code. Even when the car shakes badly and pressing the pedal without creating power.
There is also no smoke whatsoever.

The fuel pressure regulator has not been checked for now.
What is the typical symptom of a bad FPR?

 

Loss of power and bogging.

 

Evap system leak?

 

Wouldn't it throw a CEL? And there's no smell or visible leak.

Loss of power and bogging.

We will have to check it.
Is it still around the MAF area in the 2006?

I have the feeling that it has to be something mechanic more than electronic. As if something got stuck in a certain situation and then got unstuck when pushing hard up the rpm in 3rd gear.

 

I've got an 02 so I odn't know where the FPR is on your car necessarily, sorry.

 

Update!
Finally the car has been running great consistently now.
Innitially the MAF and downpipe O2 sensor were giving weird readings so they were replaced. It seemed to work but everything went bad again soon after burning half tank.
Next was to replace front O2 sensor codriver side, and finally it was the right solution.

So if you are having similar problems as I had, start by this last sensor, as I've spent now 4 month coming and going to the mechanic and 1000€ worth material and man hours.😢

 

Thank you for posting your journey with your WRX. I have been having the "EXACT" same problem for a LONG TIME and no check engine light. And for that exact reason (no cel), I have had all the mechanics and even the service manager at the largest Subaru dealer in the U.S. stumped as to what is going on. I had just got my WRX back from having the catalectic converter replaced on Thursday, which actually made it run worse for about 20 miles. I guess they have a break in period? Anyway, I made it home frustrated, and went right to the internet for more research. I found you journey here yesterday, called my local parts house and ordered the upstream O2 sensor. I picked up the O2 sensor this morning, swapped it out and took my WRX for a beautifully long test drive and it's almost a brand new car! (with 257,000 miles on it).

 

Thank you for posting your resolution to this.

I'm surprised it didn't kick a code, good to know it doesn't always.

 

+1.

This is good practice so that others can learn from your experience.

 

Sad update.
The problem is back.
Again it randomly appeared while driving slowly in the city.
Engine feels weak at low rpm and bogging a little, turbo doesn't push strong and feels like a non turbo engine.
Again all symptoms are solved when I accelerate strongly up to 4rth gear and at 4500rpm the turbo kicks suddenly.
Magically all engine misbehavings disappear and the engine feels good all rpm range.

You can imagine how pissed I am after all the money and time spent.

I would accept greatly any theory you could throw.

 

I have the exact same problem. At 4,500 rpm exactly it’s like a flip switches and I have full control of my car. I’ve checked everything. 3 years have had this problem. Intermittently right? Some days nothing and some days happens every time accelerating

 

So, a turbo vehicle isn't typically going to make any positive manifold pressure when just loading around under light throttle and low RPM. You have to get the engine under load and moving to do so. It's also not ideal to stomp the throttle in higher gear at low RPM. It can cause misfiring and over boost leading to damage.

Do you have a way to pull logs on your car? Accessport, or an opensource solution? Some scan tools will also record logs you can transfer to the PC.

 

I know, that's not how I drive. It has nothing to do with lugging the engine, the problem starts suddenly randomly.
And never throws any CEL code.

INope, I don't have the means to retrieve data from the car. I only have one of those little plugs you can use to run torque pro app on your phone.

 

The only thing I can come back around to is the oil on the plugs.

Did he happen to do a leakdown test on those cylinders? Do you have any loss of coolant or oil?

 

They did not perform a leakdown test.
I had a coolant leak on the exit pipe from the radiator, but we tightened the clamp and doesn't seem to be leaking anymore.
Why do you ask? Could this happen due to a bad HG?

 

Today I had to replace the battery that died, it was only 2 y.o. weird...
When I started the car with the new battery I noticed a persistent CEL, torque app reads P0607 – Control module -performance problem.
OK I've shat my pants now.
Could it be related or is this a new problem?

 

That might be from the battery. But it could be an issue somewhere with wiring.

 

Hello,
I've been out because of covid and other issues.
Well I put in a new battery, drove the car and then left it for two and a half weeks in the garage.
Went to start it today and surprise, the new battery has died too.
There's not juice even to start the roof light.

I clearly have some issue with the electric system.
Might it be related to the engine behaviour problems I've been having?

I'm getting really tired of spending money endlessly on this car and having problems every time I want to go for a drive.

 

An update after all this time.
I noticed a cable from the tow how that was badly covered in some cheap tape.
Took care of it with some heat shrink sleeves and moved the cable upwards to keep it away from any water that could be sprayed there.

I'm not sure this was the main problem, but I've only had a minor engine "hickup" that could be caused by low fuel on the tank and a steep ramp on a curve.

Otherwise it's been running strong and smooth. Fingers crossed and let's see what happens in the coming hot weather months.

 

Reading through this, it almost sounds like you have a blockage somewhere, whether it be air, fuel, or exhaust. However, if it was electrical, what you are describing could have been it. A short in the wrong place would do a lot of what you described.

 

Hello!

We are 4 months on now and the engine hickup has not appaered since I took care of those loose cables.
I don't know if it's just a coincidence, but I also found out and repaired recently a bad front headlight levelling sensor that was all corroded inside and had the infamous broken pin.

I would bet it was both electrical related issues that were causing some kind of short and fooling the ECU or whatever.

Crossing my finger for it to not happen ever again.

 

Well here I go again. The problem has come back.
Sudden loss of power, as if the engine could not breathe. No turbo thrust at all, feeling like a NA engine.
It struggles and hesitates strongly uphill after a hairpin.

All symptoms magically disappear or sometimes can disappear after reving al the way up from 3rd to 4th gear (doesn't always work) and all of a sudden the turbo wakes up and pulls strong again.

This time I have been able to record some data logs with an app but I think it did not record properly all data.

Here it goes: open in google sheets

Can anyone make some sense of the data recorded?
The recorded driving was: Street driving, some stops, then going uphill on a mountain road, car struggling out of hairpins, suddenly recovering power and torque, end of trip.

 

This as my MAP sensor and after cleaning she was perfect

 

I have been having this same issue with my 19 WRX. Has happened driving in 6th gear on highway doing about 100km/h and in 2nd or 3rd gear doing about 40-50km/h. When driving all of a sudden no throttle response at all and car starts to slow down, then about 5 seconds later would come back. Was happening maybe once a week, sometimes worse. Then all of a sudden, the car just kept wanting to stall out. Had to keep Revs up at lights to keep the car from stalling. Then back to normal.

Took it to Subaru dealership and tried explaining the issue. They initially said because the car isn't completely stock they would have to revert to stock then look. And because the issue would just pop up occasionally, I know it would hard for them to diagnose. I then just asked them to do whatever the recommended service was for that mileage (about 80,000km). This included injector cleaning, and carbon cleaning. This seemed to fix it. Been about 4 or 5 months, maybe more since. Started to happen again today, about 4 times during a 40 minute drive.

 

I was having the same problem did you check your map sensor? Mine was covered in oil, exact same symptoms as you.

 

MAp sensor is new and clean.
What I have stated is that the engine behaves badly when at cold start I don't let it warm up for a minute.
If I start driving (just moving the car inside the garaje) and the secondary air pump has not stopped, the car runs badly and with limited power. Until it randomly decides to drive fine again.

That's a bummer because when other people have the car, they won't wait to move the car (mechanics, etc.) so I'll suffer this bogging again.

 

Have the same issue as you and it's really crappy because it takes alot from this car

 

I am having the same issue as well. If I push the gas to hard the rpm's will shoot up with little to no power. I have to somewhat baby it to drive it. No cel's. I have to let off the gas and it feels like something grabs and I can accelerate like normal. If I press the gas and the rpm's shoot up and hold for like 3 seconds I smell something burning but it doesn't smell like oil. I only did that once.

 

Mine idles and sounds perfectly fine. I have a cobb ap, cobb sf intake and cobb charge pipe. Tuned by dmann.

 

2005 wrx ej205
hey guys, I rebuilt my motor hoping this problem would go away, but as you can guess, here I'm...
anyone figure this out? its gotta be something electrical or cloggled or near failing, I got no check engine light...

 

So I wanted to post hear to give a really good description what is happening and what i think OP and lot pf us are experiencing. I will be cruising my car is fully warmed, no cels, misfires, new plugs, walnut blast valves about 40k ago, theyre due, but ill be light throttle cruising, flat street no incline and you can hear itll almost sounds like the fuel cuts out for a few secs and you can watch the maf readings go super lean and I usually just let off the throttle give a lil tap of free rev and its gone. Im tuned by Anthony at drunkmann, have the aem lo pressure pump brand new installed, boostlabs 54x brand new by felix perf at 80k miles at 84k now. EtS full intake with grimspeed ebcs and turbo inlet and tomei full catback not just muffler but not the dp. Im gunnin for fmic or tmic and dp, but tight with turbo dying. Anyways compression is great 204 across all 4 when turbo was installed. Anyways Im coming down to believing it has something to do with the maf sensor OR more importantly Maf harness extensions, I have read alot of things about peoples maf harness extension causing all kinds of issues. Now carbon doesnt cause it, but may contribute or excacerbate it, but i know when i first got my valves blasted it still happened, plugs 2 times plus the new ones that came in it, it always still happened. So at first i thought maybe it had to do with the lo pressure factory pump which has a recall for the impeller, but I now have the Aem pump so i know its not that. I bought it 1 owner 16k miles, its been tuned by anthony since 16500k miiles and has no real problems, this is annoying. I seem to find it happens more frequent on hotter more humid days. Im down to those 2 items. Ive never had CELs or soft or hard codes stored. So has anyone come to any conclusions?

car info 2019 Subaru Wrx premium 84k miles currently bought at 16k as one owner certified subaru. Reason i paid for turbo and went aftermarket even tho under warranty is subaru has replaced my headunit, alternator, ac compressor all under warranty. I tuned it a week after i bought. They treat me right i dont expect them to replace something that i wore out. I knew the possibilities of tuning and what comes with that. The turbo lasted a good 80k before i replaced. Just to say, it wasnt smoking or anythibg like that, but I noticed it wasnt hitting full boost anymore 19.5 give or take a .5 psi and it was only hittim 17 WOT and in the morning you could hear the turbine slightly wurring against the housing so instead of letting it eat itself i dealt with it.

 

You can actually look in the intake side of the housing and see where at times the turbine blades at times were coming in really really light cpntact with the housing, creating a shiny burred surface.

 

Subaru just issued a recall on the rear cataletic converter for the 2017 WRX model year. They will replace it and reprogram the computer for free. This may be the issue that is causing the engine to run very lean and very rich at very random times. Mine will be replaced on Monday July 14th and I will let you know if that helps. I will also have the spark plugs replaced bcause it's time for that as well. 281,000 miles on it.