1999 Saturn Sl2 Picked Used Car Daughter Did Things Wanted Drive Make Sure

if that is the only code you have,then you need a new oxygen sensor,it's b1 s1 when just means it's the first 02,closest to the motor.ask for sensor 1 or the pre cat sensor.these sensors on this vehicle have a huge failure rate.

so its just slow to reply to the pcm to tell it what to do?

does the single cam motor have this problem to. scanner showing lean to rich and rich to lean counts

yes,slow response time.in our business we refer to it as a lazy 02 sensor.and your car has a huge failure rate for the b1s1 o2.

so is that why it shows lean to rich and rich to lean counts on the scanner? just changed it and deleted code. 49 bucks for bosch

Yeah i have replaced a ton of those for that code.

the switching of lean to rich and back to lean is normal,the problem is that the lazy sensor doesn't do it fast enough.

so if switching back n forth from lean to rich or rich to lean is normal why scanning one car has like 79 counts of doing this n another car has zero all the time. does any miss fires cause anything to do with that?

it all depends on the air to fuel ratio at which the car is running,the 02's job is to keep the vehicle at a 14.7 to ratio of air to fuel,which is called stoichometric ratio. but if a condition such as a vacum leak or leaking injector exists which cause an extreme rich or lean condition then the 02 will stay positive or negative to try to control the fuel trim.and yes a missfire will definately cause unusual 02 action due to the excessive amount of either raw fuel or air intering the combustion chamber.

drove car today. no codes. scanned it. had rich to lean and lean to rich counts. 131 and 144. cyl 3 had 3 misfires.egr test count 3. cam resync counts 7. a/f ratio 14/7. anything look off or pretty normal. or anything else i should look at. thanks for all the info

your welcome,the only thing i see there that i would be concerned with is the three missfires.

i had checked the plugs earlier n looked pretty good. tightened the gap a little. didnt have any misfires before i got the code for the o2 sensor.drove about thirty miles today n got the three misfires

it may clear up,i woyld drive it a couple hundred miles and see how it goes.

ok thanks

your welcome.

What kind of spark plugs do you have in there?

dont remember off hand what they were. checked gap and condition n put some anti seize on them n put them back in. do u have a recommendation for this thing. u usally answer all my saturn questions. i can check if u want or let me know what works best. want it running good n hope good on gas. my daughter will be driving it. god for bid. thanks

You don't want to use platnuim plugs in that engine they carbon foul and cause miss fires.NGK copper plugs ac delco copper or Bosch super copper plugs.

ok thanks. will check. they looked good, but will check

No problem