downpipe troubles.

[P1mpsy0r1c3]

i have CA header. i was planning on doing dp, then catback...idk much about 4 cylinders and downpipes.

[cobaltkrazy]

Originally Posted by P1mpsy0r1c3

i have CA header. i was planning on doing dp, then catback...idk much about 4 cylinders and downpipes.

remember, if you do any exhaust job, you need the cat.

since you have headers, a dp will help with the airflow.

[P1mpsy0r1c3]

what do you mean exhuast job

[ZOLOMAN]

Originally Posted by cobaltkrazy

you remove the cat, you will throw a CEL. The cobalt employs a dual O2 sensor set-up, and if the mixture to the second sensor matches the mixtire read at the first, it will think the cat is not working, and throw the code. I have heard O2 clamping may solve the problem, but am not a believer, aand i highly doubt you can tune the car enough to ignore the second sensor. My suggestion, go with a low restriction cat(high flow), they have been tested and proven not to throw CEL's on newer cars, while letting as much airflow through as possible. We followed the order of one customer, whom we warned about the issue, to remove the cat, so we did. sure enough, he came back the next day, and had to have a new cat put in, because it threw a CEL. Put in a new cat, clear the codes, and it was fine.

There is an 02 simulator that i found and have used before that works really well if you don't want a cat it sends back the proper code telling you engine that your cat is working perfectly:D here is the link O2 Oxygen Sensor Simulator - Bypass by Oxygen Simulator Performance Parts

[cobaltkrazy]

Originally Posted by P1mpsy0r1c3

what do you mean exhuast job

redo the exhaust, anything from a muffler and tip, to full system(front to back), is defined as an exhaust job. your dp, and cat back exhaust system, is termed as an "exhaust job"

[D4u2s0t]

a few things about this, 3" is WAY too big, don't go over 2.5". I had the XTC downpipe on my last car, and it was good. NOT having a cat will make the car louder, and sound more ricy. If you choose not to have a cat, you can simply have someone turn off the rear 02 sensor with HP Tuners. No need for any kind of tune other than that.

[drdave2387]

my friends rx8 he took out the cat and lost a sum power and the guys at greddy recommended him to put the cat back on cuz u need the back-pressure...Im thinking bout replacing my cat with a high flow cat which wont make it sound too ricy but it will help with the flow and still maintain enough back pressure...dont know if it helps or hurts the HP on our cars i know it helps on rotary engines tho...haha

[cobaltkrazy]

Originally Posted by D4u2s0t

a few things about this, 3" is WAY too big, don't go over 2.5". I had the XTC downpipe on my last car, and it was good. NOT having a cat will make the car louder, and sound more ricy. If you choose not to have a cat, you can simply have someone turn off the rear 02 sensor with HP Tuners. No need for any kind of tune other than that.

you do that. And let me know how long it takes before you decide to turn it back on and out in the cat again.

Originally Posted by drdave2387

my friends rx8 he took out the cat and lost a sum power and the guys at greddy recommended him to put the cat back on cuz u need the back-pressure...Im thinking bout replacing my cat with a high flow cat which wont make it sound too ricy but it will help with the flow and still maintain enough back pressure...dont know if it helps or hurts the HP on our cars i know it helps on rotary engines tho...haha

that's precisely the problem with the cobalt, loss of backpressure, loss of power.

[P1mpsy0r1c3]

Originally Posted by ZOLOMAN

There is an 02 simulator that i found and have used before that works really well if you don't want a cat it sends back the proper code telling you engine that your cat is working perfectly:D here is the link O2 Oxygen Sensor Simulator - Bypass by Oxygen Simulator Performance Parts

i might have to get these