YACT: O2 sensors

[rh71]

'97 Civic (auto) - bro got a check engine light and so he brought it in to get checked...

guy says both front and rear sensors need replacement (our 90 Accord only had 1 sensor apparently). Anyone ever heard of both sensors needing to be replaced at the same time ?

Also he said to use Denso since it's made for Japanese cars, whereas we got Bosch last time for our Accord. Looked them up at carparts and it showed this... there's before catalytic and after catalytic... are these correct ? And should I go Bosch OE, Bosch Universal, or Denso like he recommended ? Ordering first, having a buddy put them in free...

 

[NutBucket]

Bosch universal if you can solder wires, Bosch OE if you just want it to plug in.

And your civic has 2 because it had OBD2 (on-board diagnostics, 2nd generation) and your accord has OBD1 (1st generation). Now, them both going bad simultaneously sounds fishy.

 

[brtspears2]

The OBD code pulled from the car should tell you which one it is.

 

[Vic]

Originally posted by: NutBucket
Bosch universal if you can solder wires, Bosch OE if you just want it to plug in.

And your civic has 2 because it had OBD2 (on-board diagnostics, 2nd generation) and your accord has OBD1 (1st generation). Now, them both going bad simultaneously sounds fishy.

Correct. The pre-cat sensor is for the engine management to control the A/F ratio while the 2nd sensor should be just to measure the effectiveness of the cat. Both going bad at the same time is not normal.

 

[lightpants]

Originally posted by: brtspears2
The OBD code pulled from the car should tell you which one it is.

This is true, it will tell you sensor 1 or sensor 2- or both if your really unlucky.

 

[rh71]

gracias guys... I did tell him to hit Autozone for the free OBD code check... he came back and said it was the O2 sensor... he used this knowledge to make sure the dude wasn't going to rip him off... but he comes back and says it's both sensors... I'm having him go back to Autozone to order the part after a more thorough check.

thx again.

 

[rh71]

the one after the catalyst... that determines how your cat is running... will that effect performance like the other sensor would (A/F ratio) ?

the sensor after the catalyst seems to be $100 more.

 

[NutBucket]

Originally posted by: rh71
the one after the catalyst... that determines how your cat is running... will that effect performance like the other sensor would (A/F ratio) ?

the sensor after the catalyst seems to be $100 more.

It shouldn't affect performance directly however the ECU may not allow the engine to run as well as it could if that sensor is malfunctioning.

 

[rh71]

just the front... he got the feeling the guy was lying about the rear...

so...

Denso OE: $63+shipping
or
Bosch OE: $80+tax.

?

 

[Pepsi90919]

Originally posted by: NutBucket

Originally posted by: rh71
the one after the catalyst... that determines how your cat is running... will that effect performance like the other sensor would (A/F ratio) ?

the sensor after the catalyst seems to be $100 more.

It shouldn't affect performance directly however the ECU may not allow the engine to run as well as it could if that sensor is malfunctioning.

it will affect performance directly.

 

[Vic]

Originally posted by: Pepsi90919

Originally posted by: NutBucket

Originally posted by: rh71
the one after the catalyst... that determines how your cat is running... will that effect performance like the other sensor would (A/F ratio) ?

the sensor after the catalyst seems to be $100 more.

It shouldn't affect performance directly however the ECU may not allow the engine to run as well as it could if that sensor is malfunctioning.

it will affect performance directly.

Is that a Honda thing? In most cars I've seen, a faulty rear O2 sensor will just cause a cat inefficiency CEL to stick on, nothing more.

Get the Bosch.