I'm trying to decide if I should go ahead and proceed with Gestapoo's ZZP DP that I have seen in person and very tempted to buy. I know the CEL will come on w/o a doubt. So will my car be affected by performance w/o the o2 sensor?

 

What do you mean? Are you saying you want to pull your rear O2 sensor and drive around without it?

 

Rear O2 Sensor = Does nothing

 

Basically "yes". I just don't know how the car will react if I drive around w/o the o2 bung on the catless downpipe.

 

I just figured it would effect the air/fuel ratios because its looking for something and its gonna throw something out of whack in perportion. That's why I created this forum to see if its worth the hassle, if not I'm just gonna buy the DP from ZZP with or without a cat. Probably the cat like the Magnaflow Catted sinced it has good reviews and no negatives.

 

All it does is read if your cat is within working range, If it doesnt pass the test it'll set the CEL, but as far as actually "doing something" it has no purpose. Having the CEL on for it doesnt change the way the car runs at all, even unpluged the car will run perfectly fine.

The Reason I answered it like that was because he asked this.
"I know the CEL will come on w/o a doubt. So will my car be affected by performance w/o the o2 sensor?"

 

this ^^^
thread/

 

See at least someone understands lol

 

Well that gets rid of all the confusion if it doesn't do anything to the motor. Best thing I would do is remove the stock dp with the o2 sensor on and put the illegal pipe on. Gestapo can have me install it and let me go for a test drive to see how I'll like it; its another way of selling. But, I'm waiting an answer from him. Because he gave me the same answer last night, but I always like another answer from someone to be convinced.

 

why dont u just get it with the o2 bung, it wont hurt it non and u wont have to worry bout cels

 

It doesn't bother me with the CEL on. I was worry about the Air/Fuel Ratios being out of whack without the o2 sensor. After hearing from others, I'm just going to go catless w/o the o2 bung and don't have to risk the o2 sensor being dirty up from the catless.

 

I think you can just buy a defouler for it. Don't leave the O2 sensor just hanging around under there, though.

 

if you want it so bad then stop lowballing by 40 bucks, right now i have a higher offer

 

yeah, just gonna leave it inside the stock dp and probably use electrical tape to cover up the plug from messing up in the long run. here is the youtube video I don't know if I agree with how the o2 sensors work http://www.youtube.com/watch?v=NIzcztO-CCs&feature=fvw makes me believe that your car will sound like a subaru if your o2 sensor is unplugged and your car is not adjusting the proper air/fuel mixture with the fuel injectors. like this video http://www.youtube.com/watch?v=Vw1hMKkj9B4 It explains why you need the tune if you go catless with the o2 and why you don't need a tune with the catted o2 bung. here is another site I found http://auto.howstuffworks.com/question257.htm I'm just gonna order ZZP's spun metal catted and stop procrastinating.

 

well it wont mess up anything the first 02 is for air/fuel. the second is just reading ur emmissons to make sure they are good.

 

so your basically saying, if I remove the o2 sensor with the stock dp on and put a catless with the oxygen sensor unplugged it won't cause my car to go into LIMP mode or cause fuel trims to be out of whatck?

 

well there is only one way to find out isnt there, go out to ur car, unscrew ur 02 sensor, and go for a ride and see what it does. if it works, put on the new downpipe with no 02 bung and away u go, if it doesnt work, there is ur answer

 

well I'm done with the hypothesis of guessing, so I went ahead and order my catless DP from ZZP w/ the o2 bung.

 

So I was an idiot and ordered the zzp catless dp without any o2 bung. I plan on getting it tuned soon, within a week. Should I see if an exhaust shop can weld an o2 bung on there or should I just disconnect it since I'm going to get tuned anyways? Another thing to note is I have to drive 2hours away to get tuned, so do you guys think that would be an issue, running without the rear o2 sensor at all, driving 2 hours in that condition and then getting it tuned? Thanks.

 

As stated before, it doesn't matter. Not having the rear o2 will not hurt anything.

 

^as much as I want to agree with you on this one due to you being the almighty ZZP.. i have to disagree to a point.


Will the car be "hurt" from running it this way? no. so no arguing there

will there be ANY effects from running it this way? from my experiences, yes. I was running a high flow cat that threw a code (P0420 for the rear cat), and I would notice my LTFT would run about 5% richer. My hwy gas mileage went down quite drastically and when babying it on a all hwy tank I'd be lucky to see 25-26 MPG. I could clear the code, then I'd notice LTFT would go back down until the code would pop up again. This is all on stock tune FYI. Since then I have gotten tuned and disabled the rear o2 and have no issues with my fuel trims or bad MPG what-so-ever. now I see that same 25-26MPG when getting into boost quite often with a mix of city/hwy. just another one of those reasons to get tuned i guess

 

Yeah I'm going to have a local shop weld an o2 bung, hopefully an elbow or angled which I have to find by tomorrow afternoon, then do the whole muffler delete thing. Then get tuned finally! yaaaaaaay haha

 

Well I said **** it and put on the catless dp and removed the o2 sensor - so far so good! lol no cel and seems to be running the same.

 

Alright Im just gunna add my question onto this thread if you guys dont mind.

I just went to the dealer because my CEL was on and my friends equipment couldnt find what it was.

The dealer told me 2 things were wrong with my car: the rear O2 sensor (after cat converter) was bad and needed to be replaced and my wheel well liners were missing (like that when i got the car) so my stock air filter was getting wet.

From what i just read above would it be safe to assume that i would be fine without spending the $340.05 to replace the sensor???

And as for the liners im just going to buy:
07 2007 Chevrolet Cobalt Inner Fender Well - Body Mechanical & Trim - Action Crash, Left - Driver Side, Right - Passenger Side - PartsGeek

OR

GM Parts Direct: 15289944 - LINER

Just to be safe and itll help protect my injen when i reinstall it