Mazda protege with check engine

[Rocket529]

Hi I have a 01 Mazda protg MP3 for about 2 years know; it has after market headers and intake. Ive been battling a check engine since Ive bought it. First the o2 sensors went bed so i replaced them. After that the cat went bad so i replaced, it but yet the check engine still comes back on and stays on. So one of my technicians told me since both sensors had the same exhaust air flow, I need to move the second sensor back a little bit, so i put on a spark plug defouler on the bank 2 o2 sensor. The check engine went of for about 2 weeks than bank one o2 senor came on and said cat below thresh hold bank one sensor. so i replaced the sensor but yet the same thing came on.

I need help with this who ever put on after market headers on their mazda protg and went through the same issue.

 

[Tzar177]

Yes, if you have an aftermarket header you will most likely need to do the nonfouler trick(the "how-to" can be found in the how-to section of this forum) What header do you have? What cel codes were you throwing? How many miles on the car? Have you checked spark plugs? Have you done any engine cleaning like seafoam? Where are you located?

 

[Spiced MSP]

I had the same code when I put on my catless exhaust, the non fouler trick should do it. Something else must be going on if you get the code back again

 

[microman777]

How much more HP do headers give an MP3?

 

[808MP5]

How much more HP do headers give an MP3?

probably not enough to notice it....


i would guesstimate 3-5
when i installed a header back in the day on my p5 i really didn't notice any difference in power... did notice a difference in sound and the overall feel of the car