Rich and Surging on Highway

[Wicked_Sludge]

only OBD II vehicles (95 and up) have a cat efficiency monitor (O2 after the cat). his has either 2 or 1. im guessing two.

 

[adamputz]

I replaced the IAT sensor and the IAT code went away. I reset the computer and am still getting the O2 sensor codes from the memory. I went for a 15 minute drive, could it just take the computer awhile to recalibrate?

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

177 - (M) Oxygen sensor not switching - system was rich Left or Front HO2S - Fuel control

 

[Wicked_Sludge]

it could be lazy O2 sensors....but the chance of them both going out at the same time isnt very high. ive seen EEC-IV give both rich and lean codes before and its always a bit perplexing. other than checking the "usual" stuff like tune up items and checking for vacuum leaks, im not sure what to say. you did clear the continuous memory codes using the proceedure in the tech library, right?

 

[adamputz]

To clear the memory, I used the paper clip trick, ran the codes, and while the codes were running I disconnected the paper clip. I'm assuming that's what you're reffering too

 

[Wicked_Sludge]

yep, thats what i was talking about.

 

[adamputz]

well it might be time to take it in if it doesn't get any better, i'm starting to run out of ideas. Thanks for the help!

 

[Wicked_Sludge]

good luck to ya. wish i could be of more assistance.