Budders

Both o2s just went off. Didn't think a cat back could do that though. Maybe it's due it to not being driven more than 1k miles in the past year or so?

Just got her and put 300 miles on her (sort of rough).. last owner only put 1k miles on her in the past year.. maybe thats causing the codes? Bad O2s? Exhaust?

Kels88

Catbacks shouldn't throw CELs. I have never heard of that and have been through 3 so far. Could be a plethora of things to be honest. Bad quality of gas, clogged/dirty cats, etc.

seymore4

iTrader: (27)

Which codes did it throw exactly? That will help us diagnose...

Budders

I put 91 octane in it and usually get gas from reputable places such as sunoco.

p2a03 - O2 sensor circuit range / performance bank 2 sensor 1

p2a00 - O2 sensor circuit range/ performance bank 1 sensor 1

travlee

iTrader: (8)

what mods are done on it

and it is best to use 93 octane

seymore4

iTrader: (27)

clear em and see if they come back. Cars do weird things sometimes. I wouldn't expect them both to go off like that

Budders

only mechanical mods i know of are catback exhaust.. and your 100% sure it should always be 93 octane??? Thanks for the tip

travlee

iTrader: (8)

if i remember correctly on the gas cap it says use premium.... for the small dollar amount more i would just get it

Budders

I know it says premium, and Im not worried about the few extra pennies.. I just though 91 was generally the acceptable premium for sports cars due to some rural parts of the US only carrying up to 91 octane.

Syner

It's weird they both went off at the same time. Write the codes down, clear them, and see if they come back.

91 is fine, 93 is better if it's available.

Budders

Can the Z's actually take advantage of 93? If so thats pretty cool, next tank i'll fill her up with 93 and see how she runs

Budders

Cleared em and check engine light came on again.

Syner

Chances are you won't notice a difference.

How long until they came back on?

Budders

+/- 50 miles

Kels88

I ran kinetix test pipes with the 02 sensor bungs and new 02 sensors with no CEL/SES. Maybe it is time for some new 02 sensors or some HFC's/new sensors? I cleared mine on the stock cats after 119k and they came back just as you are describing within 100 miles or so.

I would check the resistance on the 02 sensors if I were you. Maybe it would save some money on new HFC's and 02 sensors (unless you want to do it )

Budders

I have one of those little code readers, gotta check if mine will do o2 readings... if not, i'll have to go borrow a modis lol

Syner

You don't need a code reader to check O2 sensors.

The guy sounds like a bit of a dolt, but it's simple and he does a decent job of explaining it.

Budders

Ah okay I see, so that test checks for voltage before the o2 sensor

Kels88

You figure it out yet?

Budders

Nope.. still not sure what to do first. I do have a multimeter so if i get a chance ill check before the o2.. do O2s get clogged up on cars not running for a year or so?