My 97 legacy 2.2 runs fine for a while then stumbles with lo-power and vibration until I stop the car, and restart the engine. then it runs good until next episode.

 

it's showing a 1507 code (idle control system malfunction (fail safe). I replaced the air control valve hose - from air cleaner bottom to ACV  (it was partially (10% +/-) obstructed with crud build-up) and I sprayed some injector cleaner into the ACV but I couldn't see any obstruction. I cleaned or replaced other hoses in that vicinity that looked bad. I also replaced the fuel filter. The engine runs fine otherwise.

 

(there is also a code 0135 - o2 sensor. and a 1325 knock sensor)

First after some research I found this article for you:

 

http://www.northursalia.com/techdocs/pdf/engine/p1507.pdf

 

You also need to understand that the knock sensor and O2 sensor failures can cause the car to run rich or lean.  

 

The O2 sensor detects how the car is running based on the exhaust so the computer can adjust correctly.  If it isn't reporting correctly the computer can't make the appropriate adjustments.

 

The knock sensor picks up all kinds of spark knock, including ones you can't hear.  Using what it detects the computer can adjust fuel/timing to correct the problem. 

 

So your dealing with multiple issues here for parts that are relatively inexpensive.  

 

Knock Sensor = under $50

 

O2 Sensor = under $80 (local but would be much cheaper online)

 

Fix both of these and read the endwrench article as well.

Thanks very much that is very helpful...  The PDF also mentions the "inhibitor switch" I think this could be contributing to the problem as well. I've had some issues with the neutral safety switch.

 

I pulled the knock sensor and it seems very clean (and simple) is that a switch that is known to fail? The most difficult part was reinstalling it while keeping dirt from falling onto the contact area.

 

Again, thanks for the useful info!

 

Regards,

CAP86

 

P.S. you mentioned "endwrench" article... is that the PDF "insider info link that you supplied, or is there some other source that I'm not aware of?

Edited May 30, 201510 yr by cap86