Contour Enthusiasts Group Archives Forums General Troubleshooting Need help with codes on 95 Mistique 2.5L

Had problems last fall passing the "E" Test. I never had any engine cel codes on the dash, bought the car used so I dont know if it even works? Car seems to run fine though...so today I picked up one of those cheap OBD1 code readers and decided to try it out. Well I pulled the following codes 172, 173, 176, 136, 117. It seems they point to the O2 sensor?? What do you make of these codes? And should I replace the O2 sensor? There is 2 sensors correct? Car runs fine, does not overheat, but when I did the "E" test last fall it failed the first test with high
( NOs )?? Gave it a good blast on the hiway and it just bearly snuck under the limit but did pass. Would these codes be the problem and what should I replace?

Thanks alot.

172 (R,M) Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control

173 (R,M) Oxygen sensor not switching - system is or was rich - Single, Right or Rear HO2S - Fuel control

176 (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control

136 (R) Oxygen sensor not switching/system lean Left or Front HO2S - Fuel control

117 (O,M) ECT sensor is/was low or grounded - ECT

Basically you need new Oxygen Sensors(2)

Ok, thanks I will pick up some new sensors and clear the codes and see what happens from there. Thanks