fouled o2 sensors.....need new?...or???

**jmatt07** · 07-07-2009, 12:53 PM

ok as some of u might know my 98 ss with h/c/i swap is bein a pain and will studder under acceleration and has no power and then studdering will stop after about 15 min of driving then be fine but will still have loss of power. it has 42# injectors now as well. have mail order tune done but was told by a couple guys on here that i could be fouling out my plugs and o2's bc i dont have a full tune yet. the 02s are brand new but its throwing codes for them. bank 1 and bank 2. So im guessin that the o2s are fouled. so my question is if they are fouled out can i clean them with carb cleaner or something and and put them back in and take it to be tuned or do i have to buy new ones.....Again....

**shady milkman** · 07-07-2009, 01:06 PM

there is no need to even start diagnosing problems and replacing stuff when you haven't even had a full tune with a h/c/i yet..get the tune...then see whats left

**Too Fast** · 07-07-2009, 01:16 PM

Originally Posted by jmatt07

ok as some of u might know my 98 ss with h/c/i swap is bein a pain and will studder under acceleration and has no power and then studdering will stop after about 15 min of driving then be fine but will still have loss of power. it has 42# injectors now as well. have mail order tune done but was told by a couple guys on here that i could be fouling out my plugs and o2's bc i dont have a full tune yet. the 02s are brand new but its throwing codes for them. bank 1 and bank 2. So im guessin that the o2s are fouled. so my question is if they are fouled out can i clean them with carb cleaner or something and and put them back in and take it to be tuned or do i have to buy new ones.....Again....

No, you can't clean them with carb clean. What is the exact code, anyway? Is it too rich/lean, or is it heater circuit failure, not responding, or what. Also, are you absolutely certain the spark plugs/wires are perfect? We've seen others here swear they are ok, only to report later that that was the issue. That will cause misfire/stuttering.

And like Shady said, you need to get a tune so they can set your F/A ratio and other things.

**jmatt07** · 07-08-2009, 06:08 AM

So i can go get a full tune with it running like this? I just dont understand how he can dyno and street tune it with it runnin like crap. And is it possible for the plugs or wires to be causing this only at certain rpm and only for like 15 min of driving?

**Spaz** · 07-08-2009, 06:28 AM

Originally Posted by jmatt07

So i can go get a full tune with it running like this? I just dont understand how he can dyno and street tune it with it runnin like crap. And is it possible for the plugs or wires to be causing this only at certain rpm and only for like 15 min of driving?

when you're getting a dyno tune a lap top will be plugged in to your pcm... from there they adjust AF ratio, tables etc... they can clear the codes prior to the tune

**cammed goat** · 07-08-2009, 06:35 AM

IIRC, the shop that tuned mine disconnected the rear O2s to make adjustments.

**Spaz** · 07-08-2009, 08:58 AM

have your rear o2's tuned "off" as well... they are useless any way..

**jmatt07** · 07-08-2009, 09:05 AM

ya i had the rear o2's deleted in the mail order tune. So just to make sure im hearin this right.....I CAN take the car to get the full tune with it running like this and hell be able to tune it right with it running bad right? im just afraid of losin 500 bucks to go up there and have him work on the car and find out that the tune wasnt the problem and then ill have a shitty runnin car and no money in my pocket.

**Too Fast** · 07-09-2009, 05:01 AM

Well, can you drive it to the tune shop? Is it running that bad? If so, maybe you could call the guy and explain. He should be able to tell you either over the phone or when you arrive with your car, just by a listen to the car, whether it is a tuning issue or something more basic like bad ignition parts that need to be taken care of before the dyno tune.

**Spaz** · 07-09-2009, 05:16 AM

Originally Posted by jmatt07

ya i had the rear o2's deleted in the mail order tune. So just to make sure im hearin this right.....I CAN take the car to get the full tune with it running like this and hell be able to tune it right with it running bad right? im just afraid of losin 500 bucks to go up there and have him work on the car and find out that the tune wasnt the problem and then ill have a shitty runnin car and no money in my pocket.

yes... they can tune it if it is running lousy... after a cam swap a car usually will stall out a lot when comming to a stop sign/red light and stuff like that... what do you mean in running bad btw???

**jmatt07** · 07-09-2009, 06:36 AM

running bad as in.....it studders really bad under acceleration and i have to take my foot off the gas then back on then back off then back on. it has no power at all. if you press the gas halfway down it doesnt studder but it sounds like its bogging down and accelerates very slowly. its weird that after about 15 min of driving on the highway like this the studdering will go away but the car still doesnt have any power.

**Spaz** · 07-09-2009, 06:45 AM

ah... sounds like it is looped in to "limp home mode"... i wouldn't worry about it... just take it easy on the car untill you can get a tune done... you're more than likely running very rich eespecially with #42 injectors... i would how ever try swaping your front 02's with the rears if you still have them... if not i'd pick up another set just to have them... it would be very good to have another set just incase come dyno day they are shot and you can just jack the car up and swap them out... make sure oyu bring a jack, jack stand s straight edsge screw driver (to unplug the wire thingy) and a wrench that is big enough to get the 02 unscrewed, and a can of penetrating grease to break the 02 free if it's stuck...