my check engine light has been coming on for about 5-6 months with me reseting in between each time, it used to throw out code 55 for the front o2 sensor but the last few times it has been shooting out 77 code for the rear o2 sensor, i have read that changing the rear o2 sensor is not worth it, becuase it doesnt affect performance
only gas milege

is this true?

does changing the rear o2 sensor only increase your mile per gallon and not increase the engine performance, i think theres some extra power my car has but is not showing yet,

for anyone who has changed their rear o2 sensor what changes to your carhave you noticed

any differences at all?


thanks for any responses

 

Changing my rear one this weekend, I will let you know if it helps anything. You say your code for the rear sensor was 77?? Mine was 0138? Any Idea's, why are they different?

 

The rear sensor only monitors the effectiveness of the cat converter. It wont affect drivability or performance.

 

My 95 ran normal when it happend....just drove with the stupid CEL light!

 

if i had typed this again... i swear to god i was going to put swears in there too