Well, my 02 WRX is over 140k (HARD) miles so a CEL is expected at some time.
Here’s the car symptoms and lead-up…last week got in the car to drive to work and noticed a bit more ‘airy’ noise coming from the engine bay (apart from the usual turbo/blow-off noise). Also had lower acceleration, engine power, and lower peak boost levels (only 2 or 3 psi lower). There was no stuttering, surging, knocking or pinging. Idle was fairly normal. Thought it was maybe an intake or exhaust leak. Figured it was something minor so I kept driving it in this condition.
Well the CEL tripped yesterday, which is nice because it allows me pinpoint the problem. Took it by Subaru and they scanned and….
P1088-Tumble Generator Valve #1 (RH) Position Sensor Circuit Low Input
This could be a number of problems. It may be simply a faulty electrical connection or bad sensor. Or it could be mechanical. The TGV valve is normally closed at idle and idling feels all right. When I gas it is when I can tell something is not operating correctly. Could the valve be stuck in the closed position? Or maybe the motor that actuates the valve shaft is not operating? If the valve is stuck in the closed position then it's probably the source of the ‘airy’ noise I’ve been hearing because the air is being forced through the small bypass port. I know the sensor sends a signal to the ECU so does the valve motor actuate based on this signal. Like if the sensor can't send the proper singal to the ECU then the ECU doesn;t send the right singal to the motor and the valves don't operate?
I’m going to do a full diagnostic this weekend to check voltages, resistances, and connections. It looks like I can do the diagnostic without removing anything. Hopefully it’s just a dirty/loose connection. Subaru says that if the sensor is bad then the whole sensor/valve assembly will need to be replaced (instead of just replacing the sensor). Is that correct?
I know that replacing the TGV will require removal of intake manifold, which I’ve been wanting to do for a while now to fix my leaky soft fuel lines. Looks like coolant and gaskets will be all I need for this IM/TGV removal and replacement.
So…Subaru wants around $260 for one TGV and I found some aftermarket pair of TGV deletes for under $200. PROS…I am in a county that doesn’t require emissions, it looks like it would be cheaper to buy this aftermarket part than buying the OEM replacement, more POWER!!! CONS…ECU tune looks like its needed??? I have an old ChipTorque Exceed ECM controller out of Australia and I don’t know if I can get a new map easily. Can I do this delete myself? I.E. removing the Butterfly valves so it’s just open all the time? I don’t really care if a CEL is on all the time, I just want my performance back. But having a CEL on all the time will not alert me to other CEL trips. That’s OK-ish.. I can feel the engine performance and know if something else is wrong.
One major question…how long can I drive like this until I cause other problems? I’m taking it easy on her for the most part.