boola1341

iTrader: (1)

My car has 91k miles on it. When I installed headers I didn't replace the 02's. What's some of the signs when your O2's are going bad. Also when cruising do your O2 sensor suppose to read in the 800 because mine jump all around. One second they read 800 then the next second they could read as low as 40 something. One more thing, do you think I could get more out of my car with a custom tune instead of the predator???

69LT1Bird

iTrader: (1)

The O2 numbers are supposed to move a lot, that is normal. A custom tune is always better. The canned tunes are just generic tunes that 90% of the population is happy with, the other 10% want to get the most out of there engine.

TedsB4Csled

iTrader: (6)

Get a custom tune. One of my O2s went bad right after header install. The car ran crappy without a proper tune. I tried hand-helds and mail order type tunes. Don't waist your money. Hundreds of people will tell you the same thing. Are the Pacesetters ceramic coated?

boola1341

iTrader: (1)

the pacesetters are painted black.

Twisted636

iTrader: (3)

i always heard when they looked real white

Frost

iTrader: (45)

Replace O2s at a minimum of every 15K miles for the best mileage and driveability. They don't fail early, they just drift out of tolerance and take your mileage with them.

HAZ-Matt

iTrader: (8)

For the best indication of the O2 health when logging, you need to make sure you log practically just the O2s and maybe the STFT for each bank so that you get the best resolution as the O2s switch rather quickly. The oscillation you see in the O2s occurs because the computer adds and subtracts fuel via the STFTs with the goal of maintaining an average AFR of 14.7 by oscillating around that value. With long tubes, a weak O2 heater, or just old O2s then the can appear to oscillate more slowly than the changes in the STFTs or they can sit near one value instead of reading like a sine wave. This is especially true when it is cold outside and you have long tubes. At that point you may end up setting an O2 Insufficient Switching code.

As far as cruising goes, if you have access to HPTuners and look in the bin file, you will find some tables that define the O2 sensor switch points. This has the sensor output in mV (ranges from 351-551 in the stock table I think) over the airflow modes, which are defined in a separate table). This value is the voltage that the computer attempts to center with the STFTs and LTFTs. AFAIK it should represent what GM believes the O2s to output at stoichiometric at each airflow mode on a completely stock car.

Scoggin Dickey

iTrader: (34)

I would agree to replace them, but not anywhere near that often. We do recommend to replace them but we will make a different recommendation based on each car's use and mod level. Each different operating environment will definitely change the life-span of an O2 sensor. A great bet is to go ahead and replace an f-body sensor when doing headers so you can go ahead and get the vette sensor since it's longer and won't need extensions

We keep most any OEM O2 sensors you could need in stock and the prices are great.

69LT1Bird

iTrader: (1)

Unless your engine has major issues or you used silcone on your gaskets and contaminated the O2 sensors, they will last from 50-70,000 miles with no degradation in performance or fuel economy, if you want to replace them at 15,000 I am sure that AC Delco, Bosch and Denso appreciate the added income.