....I'm using THREE sets of nonfoulers and it's STILL COMING ON! I am beside myself. I thought 2 sets would do it according to everyone's testimonials, but no. So I install a third set.

what do i do? I only want my CEL to come on when it's something that really needs to be addressed, not because of this. Thanks to anyone who responds.

 

Try disconnecting the battery for 24 hours. Just make sure you don't close the doors after disconnecting it ... (as in, open door, pop hood, close door, disconnect battery, close hood ... then 24 hours later, open door, pop hood, reconnect battery, close door)

 

you are kidding right? first thing you need to do is have your car checked out to find out what codes they are throwing. damaged o2 sensors might a possibility.

 

essentially reset the ECU. I have done this about three times since I installed the TPs with the 2 sets of nonfoulers. I installed the third set - the CEL actually wasn't on that day lol - and I figured though it wasn't on at that point in time, there was no way it would come back. but it did...

so you think resetting really make a difference?

 

What year is your Z? My 05 had problems with test pipes but my current 03 has none.

 

my Z is an 04.

So there is a possibility I fried my 02s?

What does everyone think...switch back to stock cats and buy new 02s if I want that problem gone? or is there a fix I don't know about...

 

bump.

and is it true your car operates below normal (power-wise) when the CEL is on??

 

^some wise advice here, you may want to have it checked out.

 

Go to AutoZone and have them check the codes
They usually do it for free, at least the one by me anyway.

Find out what the code is and then come back

 

the last time i had the code read, it was P1283 A/F Sensor. the ecu was reset, but the CEL came back a short time later, then went away. now it's back...ugh...so I am assuming it's the same code since it's been such a short period and the car is otherwise running smoothly. (i understand that's not always an indication of something being wrong or not)

but assuming that this code is correct, is it true that I am not getting the full power potential out of my car? or is it a case where the O2s just hate the TPs.

Since the O2s help control the fuel/air mixture, I have a feeling that my performance is suffering

I need this problem out of my life...even if it means getting new 02s and putting the stock cats back on, which i'd rather not do.

 

mine didn't go away for about 100 or so miles, after installing the nonfouler.

 

Agree. You are attempting to solve a test pipe problem. The problem may not be a result of the test pipes.

 

i reset the ECU and it's off at the moment. does that mean that the "problem" leaves when the CEL is off, and returns when it's on? I've never had this fragile of a time with a car before.

 

yea, i think so. When i bought my test pipes i didn't think i needed the foulers. Stupid me, the cel came on like 50 miles later or so. after i put the foulers on i disconnected the battery and pushed the brakes a few times and reconnected the battery and hasn't come on since. My advice would be if you still think it is the test pipes and you seem to be one of the few this isn't working with i think you should put back on your stock cats. If you put them on and the cel is still on you probably messed up your o2's. If it goes off well that is just really weird and you should def. get it checked out.

 

350Z_GTS, what do you mean? If it goes off...why get it checked?

 

This is crazy. Invest in a code scanner. Read the codes EVERY time you throw a CEL. You need to figure out which O2 sensor is the offender. If it's the upstream ones, then downstream non-foulers will not help. Non-foulers will only work on the downstream sensors to get them out of the 'bad' air stream. And a little research by you would not hurt. This info is all over this forum.

 

It may be an exhaust leak upstream of the sensor.

The leak actually pulls in air during the scavenge phase of the exhaust pulse and registers as a lean condition to the sensor.

This is more likely what the code is.

 

when i let off the gas at slower to moderate speeds (scavenge phase??) i hear a hissing sound. assuming it's a leak of some sort...not really sure how that's possible considering i did the install myself w/ gaskets and torqued the bolts properly.

In all honesty, it sounds pretty unique. CEL is still off after resetting the ECU though.

 

My CEL came back on today after resetting the ECU a couple weeks ago.

My situation: THREE sets of nonfoulers (2 of which are undrilled) and numerous ECU resets.

Seems like the problem goes away for a few weeks and comes back every time I reset.

My first step now is to flash the computer at auto zone and see if it's still the same o2 fault code.

What steps would you take to solve this problem if you were in my shoes? When I have a car problem, I tend to look forward to the future - plan A, B, C, etc.

Can anyone help me?? I don't understand how the CEL can be on one moment, off, then on again.

 

.....