o2 sensor question

[ASchaffer]

If my o2 sensors behind where my cats should be were messed up, would it make my car run bad, or would it just trigger the check engine light?

 

[Carl]

You might get some stuttering and hesitation, less fuel mileage. It will probably be a little down on power, but nothing drastic.

 

[ASchaffer]

ya when im accelerating slowly it stutters, and doesnt sound good... So o2 sensors would cause this then?

 

[Carl]

Yes, they could. That's not saying that it definitely is, but yes they could. Your car is probably running excessively lean or rich if your o2 sensor is bad and that gives you stuttering and hesitation problems.

Does your h-pipe have cats or not? If you are getting a check engine light with o2 sensor codes then if you have mil elim's then one is probably bad or if you do have cats if they are high flow you could trigger a light also. But if you have no Check Engine light, it could be something as simple as bad gas

 

[ASchaffer]

My H-Pipe has no cats... I did the do it yourself MIL Eliminators, maybe I didnt do a good job. These have been working fine for about 3 weeks now. Could that possibly be the problem here?

 

[Carl]

That's probably exactly what it is. If you have a bad connection or one of the components go bad, it's gonna give you that code. Also, some cars just don't respond well to those MIL's. Mil Elimanators work most of the time, but there are still cars out there that go through several sets and they still get the light anyway. Try reseting your battery and see if it comes on again. I know they have more of a tendency to come on in cold and wet weather and stay off in hot weather, if you occasionally get the light due to Mil Elim's.

 

[jstreet0204]

If my o2 sensors behind where my cats should be were messed up, would it make my car run bad, or would it just trigger the check engine light?

No, front o2's affect performance, rears do not. The rear o2's are only there to test the function of the cats.

 

[Milenko]

No, front o2's affect performance, rears do not. The rear o2's are only there to test the function of the cats.

I know I'm bringing back an old topic, but I need to.

If the front O2s are messed up, would this affect your car? Mine is hesitating and bucking, and it happened after I got my O/R X installed.

 

[RysRed96GT]

No, front o2's affect performance, rears do not. The rear o2's are only there to test the function of the cats.

the rears are only there for emissions purposes to throw the dummy CEL if the cats are bad (or missing). they have no effect on performance and arent read into the EEC for controlling air/fuel. the fronts, however, do. other things could cause the problems you indicated, but if you have high miles, then replace them. call randy at liberty ford and you can get oem's for 66 bucks each. i'd also check your MAF sensor if it's dirty. how is your idle?

 

[RysRed96GT]

this seems like an old thread. im reading ur other one and u said the o2's are unplugged?

mass air sensor (maf) is the collection tube inline with the inlet tube and the air filter. the sampling tube inside can become dirty and cause a rough idle and labored acceleration. its a quick thing to clean it. but ya gotta break the tamper proof pins to do it (use a power drill/bit and torx t20 bit)

edit: why is my post above yours?

 

[Milenko]

the rears are only there for emissions purposes to throw the dummy CEL if the cats are bad (or missing). they have no effect on performance and arent read into the EEC for controlling air/fuel. the fronts, however, do. other things could cause the problems you indicated, but if you have high miles, then replace them. call randy at liberty ford and you can get oem's for 66 bucks each. i'd also check your MAF sensor if it's dirty. how is your idle?

My idle isn't too much different, but it is. Off by about 2-300 rpms.

Idling sort of rough too. I unplugged the battery for 20 mins and the car drove like normal, so I don't know.

Where's the MAF sensor? Is it connected to and/or near the air filterr?