90 Legacy Eng. Power Loss Problem

[fuwang604]

Hello to all!! I'm new to this forum and have owned a 90 Legacy with 318000 Km for about a year now. I have recently changed the O2 sensor and clear the codes stored in the computer.
Now my problem is that when I drive the car in stop and go traffic the engine after an hour in traffic starts to hesitate, misses, and shakes, resulting in a loss of power even if I have it in wide open throttle. Absolute NO POWER at that time!! I manage to pull over and shut off the engine and wait for about 15minutes, start the car and it drives fine again. Right now it is winter and I think that when the car gets to a certain temp. something goes. No code pops up and no Check Eng. Lite(CEL) comes on.
This is not the first time this happened before when this happened, the car idles badly like as if it has a miss, when in nutral and when I put it in drive there is no power at all and it even stalls, the car restarts fine again but the problem is also there.
I did drive the car for a while one day and the CEL did come on and it said that it was Code 32 which is the O2 sensor, but I just replace a new Bosch OEM O2 sensor and the code still popped up I have not cleared the code since.
I'm really at a loss to the problem, the car runs fine when cold and warm, it is just in stop and go traffic for about an hour, slow driving, or stop, shut down, go purchase something for 10 min and come back to restart the car, that this problem happens.
I hope that there are experts out there that can identify my problem, get my car fixed and back on the road again, I have a new job starting next month and I want my legacy to run reliable again, I like driving it.
I do not know if it can be a faulty NEW O2 sensor, the coil pack or other malfunction in the system that the computer cannot see to help me diagnose my repairs to the miss in my legacy.
Thank you all in advance for your advises and Happy Motoring

[Manarius]

I bet your MAF is toast.

[fuwang604]

Gee could it be that simple?? I so far do not have a code 23 or 49 pop up yet though!! What would be a simple way to verify it?? Back probe the sensor when the problem occurs?? Clean out the sensor mind you it is probably the orginal sensor!!
I did not think that it was the coil pack since it happens only when the car gets hot and it is located on top of the intake manifold to keep it cool!! The O2 Sensor is brand new so I did not think that it came defective. I just keep on guessing though!!!
Has this happen also to you before?? Please let me know Thank you and Happy Motoring!!

[Manarius]

I would clean the sensor with Rubbing Alcohol and a Q-Tip then reset the ECU and see if that makes it goes away. Make sure you reset the ECU correctly and are rather gentle with cleaning the MAF.

I always say to clean the MAF first and if that doesn't work, replace it.

You can find procedures for resetting the ECU on Legacy777's website.

[Legacy777]

Please see this thread

http://bbs.legacycentral.org/viewtopic.php?t=30084