1slot/a408

how owuld a bad o2 sensor affect performance of car?

infinitebird

iTrader: (11)

your gas mileage will suck. Might not be any other noticeable difference though. It might run rough if it's doing something really wacky.

97Lt1TA

iTrader: (54)

car would bogg and idle rough

Blackbirdws6

iTrader: (7)

will def effect performance. replace with ac delco's

-Brian

Fastbird93

iTrader: (10)

Having just seen the extreme effects a single bad O2 can have on a car I can say that the following is possible:

EXTREMELY bad gas mileage
VERY extreme vibrations and misfiring

I thought my buddy's car was running on 4 cylinders it was running so bad. New O2, good as new.

C_Rules

iTrader: (7)

you'll get sputtering and backfiring.

1slot/a408

thanks guys...it really does sound like whats wrong with my car! gas is poor and sputters...now one last question....how to check if they are bad? can you tell by lookin at them?????

C_Rules

iTrader: (7)

i knew mine was bad because of my datalogger readings.

LT1_King

iTrader: (1)

my car is acting the same exact way. see i replaced the O2's about 4K miles ago with Bosch. i don't have any down stream just two on the Manifolds. back then i had the cat on my 94 Z. then i deleted the cat. it ran fine but then it started acting the way 1slot/a408. then it threw these codes. DTC 32, DTC 36, DTC 42. what could it be? the mechanic that i took it with said it was leading up to the PCM. could this be?

infinitebird

iTrader: (11)

You can either do a datalog (the value will appear to be stuck and not fluctuating enough), or you can unplug one or both of them. It will likely run better in open loop than in closed with a bad o2, so if the performance improves with them unplugged than you know that is the issue.

LT1_King

iTrader: (1)

when is opn loop? is it when it's cold or when it's warmed up? and another question would new O2's like Denso or Delphi be as good as the AC DELCO ones?

infinitebird

iTrader: (11)

open loop is when it's cold. The normal behaviour is that open loop is only used for the first few minutes until the engine warms up then it switches to closed. But if you unplug the sensors it will stay in open.

delphi's are the ac delco part.

LT1_King

iTrader: (1)

so they would work like the factory O2's?

infinitebird

iTrader: (11)

delphi = ac delco are the factory O2s. just a different name.

other ones do not work the same, and people usually have problems with them. stay with the oem part for o2s.

LT1_King

iTrader: (1)

would this act like this even thought it's not throwing a code for the O2's just the stuff i mentioned earlier?

infinitebird

iTrader: (11)

bad o2s do not always throw a code.

LT1_King

iTrader: (1)

i know this is gonna sound dumb but is there two EGR valves? i checked the on on the passenger side a while ago it seems to be good working properyl. does the other side have one too? or is it something else?

Formula350

iTrader: (3)

They only throw a code after a long time, for mine at least, but mines not as smart of a system IMO. Anyways you'd need a real-time scanner or data logger to see. My scanner does real time and the mV just chilled around 150 all the time. If they don't fluctuate between 100-900 (400-900 is best) then it's pretty safe to say it's bad.