My friend Sasha's car (1995 Legacy, 2.2, 5MT) is having intermittent episodes of poor performance. She has had the codes read and cleared twice, and they were the same both times:

 

PO115 Coolant Temperature Sensor

PO120 Throttle Position Sensor

PO325 Knock Sensor #1 Malfunction

PO125 Insufficient Temp Forced Loop

PO133 O2 Signal Slow Banks #1 Sensor #1

(P1200 or P1700 - Mechanic has bad handwriting) Signal to TCM Circuit

 

She has had the battery and alternator checked, per my initial advice. I am going to look at the groundwires and the alternator's wiring harness later this week. I don't know if we should suspect the computer, but I am not inclined to suspect the actual sensors named by the codes. I would appreciate any advice.

Just out of curisoty, when was the last time the O2 sensors were serviced?

The care computer has an open loop and a closed loop. Open loop is when you first start the car. Untill all the opertaing parts and seinors get all to thier happy temperitures, the car is running off a fixed program. Once the car warms up, it goes into a closed loop. This is where the car is reading all the sensors and everything has reached its operating temps.

The three things that can screw this up are, a bad coolant temp sensor, a bad o2 sensor, and maybe a bad tps. I dont think a bad TPS would throw it into a forced loop. so i would check out the other two first.

With a good manual and a ohm meter, all three can be tested.

 

nipper

thanks!

 

she just had the CTS changed and it seems to have done it.

YAY!

 

 

good deal

 

nipper